Merge pull request 'feat(ext): verify cookies in-browser before uploading (1.0.7)' (#57) from dev into main

Pre-upload verify request: after capturing the live browser cookies,
hit a known authenticated endpoint with credentials:'include' from the
extension's background context. If the platform reports we're not
logged in, abort the upload so we don't overwrite FC-side credentials
with stale data.

- platforms.js: add `verify` config per cookie-auth platform
  - hentaifoundry: HEAD /?enterAgree=1 (mirrors gallery-dl's HF
    _init_site_filters; same 401 path the operator hit 2026-06-03)
  - patreon: GET /api/current_user (clean 401 when logged out)
  - subscribestar, deviantart: no stable auth endpoint, skip verify
- cookies.js: verifyCookiesForPlatform() returns {ok, status, reason}.
  ok=true/false/null tri-state — null = verify not configured, caller
  treats as "proceed".
- background.js EXPORT_COOKIES + EXPORT_ALL_COOKIES: verify gates the
  upload; failures bubble up with the platform's name + reason.
- popup.js: success message now appends "(verified ✓)" when applicable.
- manifest + package.json: 1.0.6 → 1.0.7.

.forgejo/workflows/build.yml

@@ -242,20 +242,32 @@ jobs:
         id: tag
         run: |
           # Three trigger shapes:
-          #   refs/tags/v…   → tag-push: publish ONLY the immutable version
-          #                    tag (e.g. :v26.05.26.5). Don't touch :latest;
-          #                    that already got published by the main-push
-          #                    build for the merge commit.
-          #   refs/heads/main → push to main (incl. PR merge commits):
-          #                    publish :main + :latest (floating).
+          #   refs/tags/v…   → tag-push: opt-in milestone label (vYY.MM.DD,
+          #                    no `.N` per family release-posture rule).
+          #                    Publish ONLY the immutable version tag;
+          #                    don't touch :latest (the main-push build
+          #                    for the merge commit already did that).
+          #   refs/heads/main → push to main: publish :main + :latest
+          #                    (floating) AND :c-<short_sha> (immutable
+          #                    per-commit rollback substrate, per family
+          #                    release-posture rule "Tags are milestones,
+          #                    not gates — commit-SHA images are the
+          #                    rollback unit"). Rollback to any commit
+          #                    becomes `docker pull …:c-<sha>` without a
+          #                    release ceremony.
           #   anything else  → safety net; shouldn't fire given the `on:`
-          #                    config above (dev was dropped). Tag :dev to
-          #                    surface the unexpected run in the registry.
+          #                    config above. Tag :dev to surface the
+          #                    unexpected run in the registry.
+          # POSIX-safe substring (the runner shell is dash/BusyBox sh, not
+          # bash — `${var:0:7}` errors with "Bad substitution"; cut works
+          # everywhere). Operator-flagged 2026-06-01 after first :c-<sha>
+          # main-push build failed at this step.
+          SHORT_SHA=$(printf '%s' "$GITHUB_SHA" | cut -c1-7)
           if [ "${GITHUB_REF#refs/tags/}" != "${GITHUB_REF}" ]; then
             TAG_NAME="${GITHUB_REF#refs/tags/}"
             echo "tags=git.fabledsword.com/bvandeusen/fabledcurator:${TAG_NAME}" >> "$GITHUB_OUTPUT"
           elif [ "${GITHUB_REF##*/}" = "main" ]; then
-            echo "tags=git.fabledsword.com/bvandeusen/fabledcurator:main,git.fabledsword.com/bvandeusen/fabledcurator:latest" >> "$GITHUB_OUTPUT"
+            echo "tags=git.fabledsword.com/bvandeusen/fabledcurator:main,git.fabledsword.com/bvandeusen/fabledcurator:latest,git.fabledsword.com/bvandeusen/fabledcurator:c-${SHORT_SHA}" >> "$GITHUB_OUTPUT"
           else
             echo "tags=git.fabledsword.com/bvandeusen/fabledcurator:dev" >> "$GITHUB_OUTPUT"
           fi
@@ -286,13 +298,19 @@ jobs:
         id: tag
         run: |
           # Mirrors build-web's three-shape logic (tag-push / main-push /
-          # safety-net dev). The -ml image follows the same release cadence
-          # as the web image.
+          # safety-net dev) including the per-commit :c-<short_sha> tag
+          # on main-push per the family release-posture rule. The -ml
+          # image follows the same release cadence as the web image.
+          # POSIX-safe substring (the runner shell is dash/BusyBox sh, not
+          # bash — `${var:0:7}` errors with "Bad substitution"; cut works
+          # everywhere). Operator-flagged 2026-06-01 after first :c-<sha>
+          # main-push build failed at this step.
+          SHORT_SHA=$(printf '%s' "$GITHUB_SHA" | cut -c1-7)
           if [ "${GITHUB_REF#refs/tags/}" != "${GITHUB_REF}" ]; then
             TAG_NAME="${GITHUB_REF#refs/tags/}"
             echo "tags=git.fabledsword.com/bvandeusen/fabledcurator-ml:${TAG_NAME}" >> "$GITHUB_OUTPUT"
           elif [ "${GITHUB_REF##*/}" = "main" ]; then
-            echo "tags=git.fabledsword.com/bvandeusen/fabledcurator-ml:main,git.fabledsword.com/bvandeusen/fabledcurator-ml:latest" >> "$GITHUB_OUTPUT"
+            echo "tags=git.fabledsword.com/bvandeusen/fabledcurator-ml:main,git.fabledsword.com/bvandeusen/fabledcurator-ml:latest,git.fabledsword.com/bvandeusen/fabledcurator-ml:c-${SHORT_SHA}" >> "$GITHUB_OUTPUT"
           else
             echo "tags=git.fabledsword.com/bvandeusen/fabledcurator-ml:dev" >> "$GITHUB_OUTPUT"
           fi

alembic/versions/0029_drop_artist_copyright_ml_thresholds.py

@@ -0,0 +1,71 @@
+"""drop artist + copyright ml thresholds; lower general default to 0.50
+
+Revision ID: 0029
+Revises: 0028
+Create Date: 2026-06-01
+
+Operator-flagged 2026-06-01: the view modal's Suggestions panel hides
+most general-category predictions because the default threshold is
+0.95. Lowering the default to 0.50 (matches character) so general
+suggestions surface more aggressively; the value remains tunable in
+Settings → ML.
+
+Same change retires two ML suggestion categories whose Tag.kind
+surfaces are unused:
+
+- `artist`: retired in FC-2d-vii-c — artist identity is acquisition-
+  derived (image_record.artist_id), never ML-inferred. The threshold
+  column was a leftover from before that retirement.
+- `copyright`: retired 2026-06-01 — the app uses `fandom` for the
+  franchise/copyright concept (per TagsView.vue's doc comment); no
+  Tag rows of kind=copyright exist, and the threshold column never
+  fed anything user-visible.
+
+Both columns are dropped from ml_settings; the existing row's
+suggestion_threshold_general value is bumped from 0.95 to 0.50 iff
+it's still at the old default, so deployed installs pick up the new
+UX without overriding any operator tuning.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+from sqlalchemy import text
+
+revision: str = "0029"
+down_revision: Union[str, None] = "0028"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Bump the general threshold for installs still at the old default.
+    op.execute(text(
+        "UPDATE ml_settings "
+        "SET suggestion_threshold_general = 0.50 "
+        "WHERE id = 1 AND suggestion_threshold_general = 0.95"
+    ))
+    op.drop_column("ml_settings", "suggestion_threshold_artist")
+    op.drop_column("ml_settings", "suggestion_threshold_copyright")
+
+
+def downgrade() -> None:
+    # Restore the columns with their prior defaults. The bump from
+    # 0.95 → 0.50 isn't reversible without remembering whether the
+    # operator had explicitly set 0.95 (unlikely — that was just the
+    # default) so we leave the current general value as-is.
+    from sqlalchemy import Column, Float
+
+    op.add_column(
+        "ml_settings",
+        Column(
+            "suggestion_threshold_artist",
+            Float, nullable=False, server_default="0.30",
+        ),
+    )
+    op.add_column(
+        "ml_settings",
+        Column(
+            "suggestion_threshold_copyright",
+            Float, nullable=False, server_default="0.50",
+        ),
+    )

alembic/versions/0030_nullable_post_source_id_denorm_artist_id.py

@@ -0,0 +1,145 @@
+"""nullable post.source_id + denormalized post.artist_id; retire sidecar synthetics
+
+Revision ID: 0030
+Revises: 0029
+Create Date: 2026-06-01
+
+Operator-asked 2026-06-01 after the Dymkens orphan investigation: the
+sidecar synthetic Source pattern (`sidecar:<platform>:<slug>` rows
+with enabled=false) was technically correct but misled the operator
+into thinking they had phantom subscriptions. The synthetics existed
+solely to satisfy `Post.source_id NOT NULL` for filesystem-imported
+content with no real subscription.
+
+This migration makes the data model honest:
+
+1. **Post gets a denormalized `artist_id` column** so artist filters
+   work without traversing `Post → Source.artist_id`. Backfilled from
+   the existing Source linkage, then NOT NULL'd.
+2. **`Post.source_id` becomes nullable**, FK ondelete `CASCADE` → `SET
+   NULL`. Deleting a Source detaches its Posts instead of destroying
+   imported content (semantically: subscription ends, archive stays).
+3. **`ImageProvenance.source_id` becomes nullable** with the same FK
+   semantic change.
+4. **Sidecar synthetic Sources are deleted** — first NULL out the
+   FKs from Post + ImageProvenance pointing at them (so the implicit
+   CASCADE doesn't fire), then delete. DownloadEvent FK is unchanged
+   (still CASCADE'd, NOT NULL'd) — synthetics have `enabled=false`
+   so no events exist for them.
+
+Uniqueness handling: the existing `uq_post_source_external_id`
+(source_id, external_post_id) keeps working for source-bound Posts
+(Postgres treats NULL != NULL so NULL-source rows aren't deduped by
+it). A second partial unique index covers the NULL-source case on
+(artist_id, external_post_id) so filesystem-imported posts still
+dedupe within an artist.
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy import text
+
+revision: str = "0030"
+down_revision: Union[str, None] = "0029"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # Step 1: add Post.artist_id, initially nullable for backfill.
+    # FK naming follows the Base.metadata naming_convention
+    # (fk_<table>_<column>_<referred_table>) — alembic 0001 set this up.
+    op.add_column(
+        "post",
+        sa.Column("artist_id", sa.Integer, nullable=True),
+    )
+    op.create_foreign_key(
+        "fk_post_artist_id_artist", "post", "artist",
+        ["artist_id"], ["id"], ondelete="CASCADE",
+    )
+
+    # Step 2: backfill from Source.artist_id (every existing Post has a
+    # Source today, so every row gets populated).
+    conn.execute(text("""
+        UPDATE post p
+        SET artist_id = s.artist_id
+        FROM source s
+        WHERE p.source_id = s.id AND p.artist_id IS NULL
+    """))
+
+    # Sanity: count any remaining NULLs. Should be zero pre-this-migration.
+    remaining = conn.execute(text(
+        "SELECT COUNT(*) FROM post WHERE artist_id IS NULL"
+    )).scalar_one()
+    if remaining:
+        raise RuntimeError(
+            f"alembic 0030: {remaining} post rows have no resolvable "
+            f"artist_id after backfill. Investigate before continuing."
+        )
+
+    # Step 3: enforce NOT NULL + add index for artist-filter queries.
+    op.alter_column("post", "artist_id", nullable=False)
+    op.create_index("ix_post_artist_id", "post", ["artist_id"])
+
+    # Step 4: relax post.source_id + flip FK to SET NULL. The original FK
+    # name from alembic 0001 is `fk_post_source_id_source` per the
+    # NAMING_CONVENTION in models/base.py.
+    op.alter_column("post", "source_id", nullable=True)
+    op.drop_constraint("fk_post_source_id_source", "post", type_="foreignkey")
+    op.create_foreign_key(
+        "fk_post_source_id_source", "post", "source",
+        ["source_id"], ["id"], ondelete="SET NULL",
+    )
+
+    # Step 5: relax image_provenance.source_id + flip FK to SET NULL.
+    op.alter_column("image_provenance", "source_id", nullable=True)
+    op.drop_constraint(
+        "fk_image_provenance_source_id_source", "image_provenance",
+        type_="foreignkey",
+    )
+    op.create_foreign_key(
+        "fk_image_provenance_source_id_source", "image_provenance", "source",
+        ["source_id"], ["id"], ondelete="SET NULL",
+    )
+
+    # Step 6: partial unique index on (artist_id, external_post_id) for
+    # NULL-source Posts. The existing uq_post_source_external_id keeps
+    # guarding source-bound rows; NULL-source rows now dedupe within
+    # an artist.
+    op.execute(
+        "CREATE UNIQUE INDEX uq_post_artist_external_id_null_source "
+        "ON post (artist_id, external_post_id) "
+        "WHERE source_id IS NULL"
+    )
+
+    # Step 7: retire sidecar synthetic Sources. NULL out the references
+    # FIRST (the new FK is SET NULL so CASCADE wouldn't fire anyway, but
+    # being explicit makes the intent clear). Then delete the synthetic
+    # source rows. Any DownloadEvent rows under synthetics CASCADE-die
+    # with the source — synthetics have enabled=false so there shouldn't
+    # be any in practice.
+    conn.execute(text("""
+        UPDATE post
+        SET source_id = NULL
+        WHERE source_id IN (SELECT id FROM source WHERE url LIKE 'sidecar:%')
+    """))
+    conn.execute(text("""
+        UPDATE image_provenance
+        SET source_id = NULL
+        WHERE source_id IN (SELECT id FROM source WHERE url LIKE 'sidecar:%')
+    """))
+    deleted = conn.execute(text(
+        "DELETE FROM source WHERE url LIKE 'sidecar:%' RETURNING id"
+    )).rowcount
+    print(f"alembic 0030: deleted {deleted} sidecar synthetic source rows")
+
+
+def downgrade() -> None:
+    # Lossy migration — the deleted sidecar synthetics can't be
+    # restored from the orphan post.source_id / image_provenance.source_id
+    # values, and the partial unique index encodes a constraint that
+    # NULL-source Posts may now exist. No safe downgrade.
+    pass

alembic/versions/0031_source_backfill_runs_remaining.py

@@ -0,0 +1,45 @@
+"""source.backfill_runs_remaining: sticky deep-scan mode
+
+Revision ID: 0031
+Revises: 0030
+Create Date: 2026-06-01
+
+Tick vs backfill mode for subscription downloads. When
+`backfill_runs_remaining > 0`, the next N download runs use
+`skip: True` + 30-min timeout (walk full history). When 0, runs use
+`skip: "exit:20"` + 14.5-min timeout (catch-up mode, exits early once
+20 contiguous archived items are seen).
+
+Operator-flagged 2026-06-01 (Knuxy run #38887): a creator with ~550
+archived posts saturates the 870s catch-up timeout even when there is
+no new content, because gallery-dl's default `skip: True` keeps walking.
+Tick mode short-circuits that; backfill mode is the explicit opt-in for
+deep history scans.
+
+Default 0 (all existing subscriptions start in tick mode).
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0031"
+down_revision: Union[str, None] = "0030"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "source",
+        sa.Column(
+            "backfill_runs_remaining",
+            sa.Integer,
+            nullable=False,
+            server_default="0",
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("source", "backfill_runs_remaining")

alembic/versions/0032_source_error_type.py

@@ -0,0 +1,41 @@
+"""source.error_type: surface ErrorType taxonomy in FailingSourcesCard
+
+Revision ID: 0032
+Revises: 0031
+Create Date: 2026-06-02
+
+Audit 2026-06-02: the backend computes 13 ErrorType categories (auth_error,
+rate_limited, not_found, access_denied, validation_failed, etc.) and
+stamps each one on DownloadEvent.metadata, but the Source row only carried
+the free-text last_error. Operators couldn't bulk-triage failing sources
+("all auth_error → rotate cookies, all rate_limited → just wait") without
+opening Logs per row.
+
+This column receives the last error_type from _update_source_health
+and gets cleared on a successful run. Nullable + indexed so the failing-
+sources rollup can filter/group cheaply.
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0032"
+down_revision: Union[str, None] = "0031"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "source",
+        sa.Column("error_type", sa.String(length=32), nullable=True),
+    )
+    op.create_index(
+        "ix_source_error_type", "source", ["error_type"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_source_error_type", table_name="source")
+    op.drop_column("source", "error_type")

alembic/versions/0033_suggestion_threshold_default_070.py

@@ -0,0 +1,48 @@
+"""suggestion_threshold default 0.50 → 0.70
+
+Revision ID: 0033
+Revises: 0032
+Create Date: 2026-06-02
+
+Operator-flagged 2026-06-02 — the 0.50 default (set on 2026-06-01) is
+too noisy in practice; raise to 0.70 for both suggestion categories.
+
+Only conditionally updates singletons whose current value is still the
+2026-06-01 default (0.50). Operators who deliberately tuned their row
+to some other value (0.55, 0.65, 0.80, etc. via the Settings UI) keep
+their pick — the migration only catches the unchanged-default case.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+revision: str = "0033"
+down_revision: Union[str, None] = "0032"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.execute(
+        "UPDATE ml_settings "
+        "SET suggestion_threshold_character = 0.70 "
+        "WHERE id = 1 AND suggestion_threshold_character = 0.50"
+    )
+    op.execute(
+        "UPDATE ml_settings "
+        "SET suggestion_threshold_general = 0.70 "
+        "WHERE id = 1 AND suggestion_threshold_general = 0.50"
+    )
+
+
+def downgrade() -> None:
+    op.execute(
+        "UPDATE ml_settings "
+        "SET suggestion_threshold_character = 0.50 "
+        "WHERE id = 1 AND suggestion_threshold_character = 0.70"
+    )
+    op.execute(
+        "UPDATE ml_settings "
+        "SET suggestion_threshold_general = 0.50 "
+        "WHERE id = 1 AND suggestion_threshold_general = 0.70"
+    )

backend/app/api/extension.py

@@ -57,6 +57,24 @@ def _sha256(path: Path) -> str:
     return h.hexdigest()
 
 
+@extension_bp.route("/probe", methods=["GET"])
+async def probe_source():
+    """Read-only resolution of a creator-page URL: tells the extension
+    whether this URL is already a Source, is for an Artist that exists
+    but with a different URL, is brand new, or doesn't match any known
+    platform pattern. Drives the content-script chip's color/copy
+    BEFORE the operator clicks, so the button can show 'already added'
+    without requiring an add-attempt."""
+    url = (request.args.get("url") or "").strip()
+    if not url:
+        return _bad("invalid_body", detail="url query parameter is required")
+    async with get_session() as session:
+        if not await _ext_key_required(session):
+            return _bad("unauthorized", status=401)
+        result = await ExtensionService(session).probe(url)
+    return jsonify(result)
+
+
 @extension_bp.route("/quick-add-source", methods=["POST"])
 async def quick_add_source():
     body = await request.get_json(silent=True)

backend/app/api/gallery.py

@@ -43,7 +43,6 @@ async def scroll():
                     "height": i.height,
                     "created_at": i.created_at.isoformat(),
                     "posted_at": i.posted_at.isoformat() if i.posted_at else None,
-                    "effective_date": i.effective_date.isoformat(),
                     "thumbnail_url": i.thumbnail_url,
                     "artist": i.artist,
                 }

backend/app/api/import_admin.py

@@ -35,10 +35,26 @@ async def trigger_scan():
 @import_admin_bp.route("/status", methods=["GET"])
 async def status():
     async with get_session() as session:
+        # Active batch = running batch that still has outstanding work.
+        # Plain "most recent running" picks freshly-created scans that
+        # enqueued zero new files and hides the older batch that's
+        # actually being processed. Mirrors the EXISTS predicate
+        # /api/system/stats already uses (api/settings.py:145-160).
+        # Audit 2026-06-02 — /api/import/status and /api/system/stats
+        # used to disagree on the active-batch predicate; the UI banner
+        # said "Scanning…" indefinitely while the stats card said idle.
         active = (
             await session.execute(
                 select(ImportBatch)
-                .where(ImportBatch.status == "running")
+                .where(
+                    ImportBatch.status == "running",
+                    select(ImportTask.id)
+                    .where(
+                        ImportTask.batch_id == ImportBatch.id,
+                        ImportTask.status.in_(["pending", "queued", "processing"]),
+                    )
+                    .exists(),
+                )
                 .order_by(ImportBatch.started_at.desc())
                 .limit(1)
             )

backend/app/api/ml_admin.py

@@ -9,9 +9,7 @@ ml_admin_bp = Blueprint("ml_admin", __name__, url_prefix="/api/ml")
 
 
 _EDITABLE = (
-    "suggestion_threshold_artist",
     "suggestion_threshold_character",
-    "suggestion_threshold_copyright",
     "suggestion_threshold_general",
     "centroid_similarity_threshold",
     "min_reference_images",
@@ -28,9 +26,7 @@ async def get_settings():
         ).scalar_one()
     return jsonify(
         {
-            "suggestion_threshold_artist": s.suggestion_threshold_artist,
             "suggestion_threshold_character": s.suggestion_threshold_character,
-            "suggestion_threshold_copyright": s.suggestion_threshold_copyright,
             "suggestion_threshold_general": s.suggestion_threshold_general,
             "centroid_similarity_threshold": s.centroid_similarity_threshold,
             "min_reference_images": s.min_reference_images,

backend/app/api/sources.py

@@ -120,6 +120,31 @@ async def delete_source(source_id: int):
     return "", 204
 
 
+@sources_bp.route("/<int:source_id>/backfill", methods=["POST"])
+async def set_backfill(source_id: int):
+    """Plan #544: arm a source for backfill mode for the next N download
+    runs. Body: `{"runs": int}` (1..10, default 3). Returns the updated
+    source dict. While backfill_runs_remaining > 0, downloads use
+    gallery-dl's full-walk config (skip: True + 30-min timeout) instead
+    of the catch-up default (skip: "exit:20" + 14.5-min timeout)."""
+    payload = await request.get_json(silent=True) or {}
+    runs = payload.get("runs", 3)
+    try:
+        runs = int(runs)
+    except (TypeError, ValueError):
+        return _bad("invalid_runs", detail="runs must be an integer")
+    async with get_session() as session:
+        try:
+            record = await SourceService(session).set_backfill_runs(
+                source_id, runs,
+            )
+        except LookupError:
+            return _bad("not_found", status=404)
+        except ValueError as exc:
+            return _bad("invalid_runs", detail=str(exc))
+    return jsonify(record.to_dict())
+
+
 @sources_bp.route("/<int:source_id>/check", methods=["POST"])
 async def check_source(source_id: int):
     """FC-3c: enqueue a download for this source.

backend/app/api/tags.py

@@ -245,6 +245,12 @@ async def merge_tag(source_id: int):
         from ..tasks.ml import apply_allowlist_tags
 
         apply_allowlist_tags.delay(tag_id=result.target_id)
+    # Tag merge invalidates the target's centroid (the merged-in source
+    # tag's images now contribute to it). Daily list_drifted catches it
+    # within 24h, but eager recompute closes the suggestion-quality dip
+    # in the meantime. Audit 2026-06-02.
+    from ..tasks.ml import recompute_centroid
+    recompute_centroid.delay(result.target_id)
     return jsonify(
         {
             "target": {

backend/app/api/thumbnails.py

@@ -1,5 +1,7 @@
 """Thumbnail admin API: backfill trigger."""
 
+import asyncio
+
 from quart import Blueprint, jsonify
 
 thumbnails_bp = Blueprint("thumbnails", __name__, url_prefix="/api/thumbnails")
@@ -7,7 +9,20 @@ thumbnails_bp = Blueprint("thumbnails", __name__, url_prefix="/api/thumbnails")
 
 @thumbnails_bp.route("/backfill", methods=["POST"])
 async def trigger_backfill():
-    from ..tasks.thumbnail import backfill_thumbnails
+    """Run the backfill scan synchronously, return the counts. The actual
+    thumbnail generation work is still off-loaded to the thumbnail Celery
+    queue via `generate_thumbnail.delay()` per missing row — so this
+    handler is fast even on a 100k-image library (a scan is just SELECT
+    id, thumbnail_path + a file.stat() per row, no heavy work).
 
-    r = backfill_thumbnails.delay()
-    return jsonify({"celery_task_id": r.id}), 202
+    Operator-flagged 2026-06-01: the previous fire-and-forget shape
+    returned `{celery_task_id}` only, so the admin UI had no idea whether
+    backfill found 0 or 5000 candidates — \"found nothing\" was
+    indistinguishable from \"the worker isn't picking up the task.\""""
+    from ..tasks.thumbnail import _run_backfill_scan
+
+    # Sync scan inside an executor so we don't block the event loop.
+    counts = await asyncio.get_running_loop().run_in_executor(
+        None, _run_backfill_scan,
+    )
+    return jsonify(counts), 200

backend/app/celery_app.py

@@ -105,6 +105,41 @@ def make_celery() -> Celery:
                 "task": "backend.app.tasks.backup.prune_backups",
                 "schedule": 86400.0,  # daily
             },
+            # Audit 2026-06-02 — three new per-entity recovery sweeps.
+            # Each runs every 5 min like the other recover_stalled_*
+            # sweeps; each is a no-op when nothing is stuck.
+            "recover-stalled-backup-runs": {
+                "task": "backend.app.tasks.maintenance.recover_stalled_backup_runs",
+                "schedule": 300.0,
+            },
+            "recover-stalled-library-audit-runs": {
+                "task": "backend.app.tasks.maintenance.recover_stalled_library_audit_runs",
+                "schedule": 300.0,
+            },
+            "recover-stalled-import-batches": {
+                "task": "backend.app.tasks.maintenance.recover_stalled_import_batches",
+                "schedule": 300.0,
+            },
+            # Audit 2026-06-02 — daily retention for two entities
+            # whose terminal rows otherwise accumulate forever.
+            "prune-library-audit-runs": {
+                "task": "backend.app.tasks.maintenance.prune_library_audit_runs",
+                "schedule": 86400.0,
+            },
+            "prune-import-batches": {
+                "task": "backend.app.tasks.maintenance.prune_import_batches",
+                "schedule": 86400.0,
+            },
+            # Audit 2026-06-02 — backfill_thumbnails's docstring claimed
+            # "periodic Beat" but the entry was never registered, so the
+            # library got no self-healing thumbnail repair; only the
+            # manual admin-UI button fired it. Daily cadence is gentle
+            # (the task is idempotent and only enqueues regen for rows
+            # whose stored thumbnails are missing or corrupt).
+            "backfill-thumbnails-daily": {
+                "task": "backend.app.tasks.thumbnail.backfill_thumbnails",
+                "schedule": 86400.0,
+            },
         },
         timezone="UTC",
     )

backend/app/celery_signals.py

@@ -54,7 +54,14 @@ _INT32_MIN = -2_147_483_648
 
 def _queue_for(task) -> str:
     """Reverse the task→queue routing from celery_app.task_routes.
-    Keep in sync if task_routes is reordered."""
+    Keep in sync if task_routes is reordered.
+
+    Audit 2026-06-02: backup/admin/library_audit prefixes were
+    missing here even though task_routes sent all three to
+    'maintenance'. The TaskRun.queue column then lied for those
+    rows (claimed 'default') so per-queue dashboard filters and
+    per-queue threshold overrides silently missed them.
+    """
     name = getattr(task, "name", "") or ""
     if name.startswith("backend.app.tasks.import_file."):
         return "import"
@@ -66,7 +73,12 @@ def _queue_for(task) -> str:
         return "download"
     if name.startswith("backend.app.tasks.scan."):
         return "scan"
-    if name.startswith("backend.app.tasks.maintenance."):
+    if name.startswith((
+        "backend.app.tasks.maintenance.",
+        "backend.app.tasks.backup.",
+        "backend.app.tasks.admin.",
+        "backend.app.tasks.library_audit.",
+    )):
         return "maintenance"
     return "default"
 

backend/app/models/image_provenance.py

@@ -34,8 +34,12 @@ class ImageProvenance(Base):
     post_id: Mapped[int] = mapped_column(
         ForeignKey("post.id", ondelete="CASCADE"), nullable=False, index=True
     )
-    source_id: Mapped[int] = mapped_column(
-        ForeignKey("source.id", ondelete="CASCADE"), nullable=False, index=True
+    # Nullable since alembic 0030 — provenance rows for filesystem-imported
+    # content with no subscription have NULL source_id. FK ondelete SET
+    # NULL so deleting a Source detaches its provenance rows instead of
+    # destroying the linkage between image and post.
+    source_id: Mapped[int | None] = mapped_column(
+        ForeignKey("source.id", ondelete="SET NULL"), nullable=True, index=True
     )
     captured_metadata: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     captured_at: Mapped[datetime] = mapped_column(

backend/app/models/ml_settings.py

@@ -15,17 +15,15 @@ class MLSettings(Base):
     __table_args__ = (CheckConstraint("id = 1", name="singleton"),)
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True)
-    suggestion_threshold_artist: Mapped[float] = mapped_column(
-        Float, nullable=False, default=0.30
-    )
     suggestion_threshold_character: Mapped[float] = mapped_column(
-        Float, nullable=False, default=0.50
-    )
-    suggestion_threshold_copyright: Mapped[float] = mapped_column(
-        Float, nullable=False, default=0.50
+        Float, nullable=False, default=0.70
     )
+    # Default raised 0.50 → 0.70 on 2026-06-02 — operator-flagged 0.50
+    # surfaced too many low-confidence picks; 0.70 keeps the rail
+    # signal-rich while still surfacing more than the original 0.95
+    # which hid almost everything. Operator-tunable via Settings → ML.
     suggestion_threshold_general: Mapped[float] = mapped_column(
-        Float, nullable=False, default=0.95
+        Float, nullable=False, default=0.70
     )
     centroid_similarity_threshold: Mapped[float] = mapped_column(
         Float, nullable=False, default=0.55

backend/app/models/post.py

@@ -1,6 +1,9 @@
-"""Post — provenance anchor for content downloaded from a Source.
+"""Post — provenance anchor for one creator post (may contain many images).
 
-A Post is one creator post; it may contain many images/videos.
+`source_id` is nullable since alembic 0030 — filesystem-imported posts
+with no live subscription have NULL source_id. `artist_id` is the
+denormalized always-present link to the creator (added in 0030 so
+artist-filter queries don't depend on the Source detour).
 """
 
 from datetime import datetime
@@ -14,12 +17,25 @@ from .base import Base
 class Post(Base):
     __tablename__ = "post"
     __table_args__ = (
+        # Source-bound dedup. Postgres treats NULL != NULL so rows
+        # with source_id IS NULL aren't deduped by this constraint;
+        # the partial unique index `uq_post_artist_external_id_null_source`
+        # (created in alembic 0030) covers that case via
+        # (artist_id, external_post_id).
         UniqueConstraint("source_id", "external_post_id", name="uq_post_source_external_id"),
     )
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True)
-    source_id: Mapped[int] = mapped_column(
-        ForeignKey("source.id", ondelete="CASCADE"), nullable=False, index=True
+    source_id: Mapped[int | None] = mapped_column(
+        ForeignKey("source.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    # Denormalized; always equals source.artist_id when source_id is set
+    # (the importer is responsible for keeping them consistent on insert).
+    # Filter queries (artist detail, artist-scoped posts feed) use this
+    # directly instead of joining through Source.
+    artist_id: Mapped[int] = mapped_column(
+        ForeignKey("artist.id", ondelete="CASCADE"),
+        nullable=False, index=True,
     )
     external_post_id: Mapped[str] = mapped_column(String(128), nullable=False)
     post_url: Mapped[str | None] = mapped_column(Text, nullable=True)

backend/app/models/source.py

@@ -26,7 +26,21 @@ class Source(Base):
 
     last_checked_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
     last_error: Mapped[str | None] = mapped_column(Text, nullable=True)
+    # alembic 0032: last ErrorType category (auth_error, rate_limited,
+    # not_found, ...). Lets FailingSourcesCard surface the taxonomy as
+    # a colored chip so operators can bulk-triage by error class. Set
+    # by _update_source_health alongside last_error; cleared on 'ok'.
+    error_type: Mapped[str | None] = mapped_column(String(32), nullable=True, index=True)
     check_interval_override: Mapped[int | None] = mapped_column(Integer, nullable=True)
     consecutive_failures: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
 
+    # alembic 0031: sticky deep-scan budget. When > 0, the next N download
+    # runs use gallery-dl's full-walk config (skip: True + 1800s timeout);
+    # when 0, runs use tick mode (skip: "exit:20" + 870s, exits early once
+    # 20 contiguous archived items are seen). Auto-decrements per run, with
+    # an auto-reset to 0 on clean exit + zero downloads (queue drained).
+    backfill_runs_remaining: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=0, server_default="0",
+    )
+
     artist = relationship("Artist", back_populates="sources")

backend/app/services/artist_service.py

@@ -58,13 +58,17 @@ class ArtistService:
             )
         ).scalar_one()
 
+        # Posts under this artist that have at least one image attached.
+        # Use Post.artist_id (alembic 0030) for the artist filter; keep
+        # the ImageProvenance JOIN so date bounds reflect only image-
+        # bearing posts (matches the original semantic). NULL-source
+        # posts now surface too.
         date_row = (
             await self.session.execute(
                 select(func.min(Post.post_date), func.max(Post.post_date))
                 .select_from(Post)
                 .join(ImageProvenance, ImageProvenance.post_id == Post.id)
-                .join(Source, Source.id == ImageProvenance.source_id)
-                .where(Source.artist_id == aid)
+                .where(Post.artist_id == aid)
             )
         ).first()
         dmin, dmax = date_row if date_row else (None, None)
@@ -98,14 +102,14 @@ class ArtistService:
             )
         ).all()
 
+        # Same Post.artist_id direct filter — counts NULL-source posts too.
         month = func.date_trunc("month", Post.post_date).label("m")
         activity = (
             await self.session.execute(
                 select(month, func.count(func.distinct(ImageProvenance.image_record_id)))
                 .select_from(Post)
                 .join(ImageProvenance, ImageProvenance.post_id == Post.id)
-                .join(Source, Source.id == ImageProvenance.source_id)
-                .where(and_(Source.artist_id == aid, Post.post_date.isnot(None)))
+                .where(and_(Post.artist_id == aid, Post.post_date.isnot(None)))
                 .group_by(month)
                 .order_by(month)
             )
@@ -114,9 +118,7 @@ class ArtistService:
         post_count = (
             await self.session.execute(
                 select(func.count(func.distinct(Post.id)))
-                .select_from(Post)
-                .join(Source, Source.id == Post.source_id)
-                .where(Source.artist_id == aid)
+                .where(Post.artist_id == aid)
             )
         ).scalar_one()
 
@@ -206,27 +208,32 @@ class ArtistService:
         )
 
     async def find_or_create(self, name: str) -> tuple[Artist, bool]:
-        """Return (artist, created). Slug-keyed; idempotent under races."""
+        """Return (artist, created). Slug-keyed; idempotent under races.
+
+        Audit 2026-06-02: switched from session.rollback() to a
+        begin_nested savepoint + IntegrityError recovery so a lost
+        race doesn't unwind the calling request's surrounding work.
+        Mirrors importer._get_or_create.
+        """
         cleaned = (name or "").strip()
         if not cleaned:
             raise ValueError("artist name must not be empty")
         slug = slugify(cleaned)
 
-        existing = (await self.session.execute(
-            select(Artist).where(Artist.slug == slug)
-        )).scalar_one_or_none()
+        select_existing = select(Artist).where(Artist.slug == slug)
+        existing = (await self.session.execute(select_existing)).scalar_one_or_none()
         if existing is not None:
             return existing, False
 
-        artist = Artist(name=cleaned, slug=slug)
-        self.session.add(artist)
+        sp = await self.session.begin_nested()
         try:
+            artist = Artist(name=cleaned, slug=slug)
+            self.session.add(artist)
             await self.session.flush()
+            await sp.commit()
         except IntegrityError:
-            await self.session.rollback()
-            existing = (await self.session.execute(
-                select(Artist).where(Artist.slug == slug)
-            )).scalar_one()
+            await sp.rollback()
+            existing = (await self.session.execute(select_existing)).scalar_one()
             return existing, False
         await self.session.commit()
         return artist, True

backend/app/services/cleanup_service.py

@@ -11,7 +11,7 @@ the one-and-done GS/IR migration tooling.)
 """
 from __future__ import annotations
 
-from datetime import UTC, datetime
+from datetime import UTC, datetime, timedelta
 from pathlib import Path
 from typing import Any
 
@@ -187,10 +187,14 @@ def unlink_image_files(
             out["thumbnail"] = True
         except OSError:
             out["thumbnail"] = False
-    # Convention thumbs dir — try all extensions; missing OK.
+    # Convention thumbs dir — try both extensions thumbnailer writes
+    # (.jpg for opaque, .png for alpha). `.webp` used to be in this
+    # tuple but the thumbnailer never writes it (operator-flagged in
+    # the 2026-06-02 audit) — keep the tuple aligned with what
+    # actually lands on disk.
     if image.sha256:
         bucket = image.sha256[:3]
-        for ext in ("jpg", "png", "webp"):
+        for ext in ("jpg", "png"):
             try:
                 (images_root / "thumbs" / bucket / f"{image.sha256}.{ext}").unlink(
                     missing_ok=True,
@@ -354,18 +358,35 @@ def prune_unused_tags(session: Session, *, dry_run: bool = False) -> dict:
     Returns:
       dry_run=True:  {"count": N, "sample_names": [first 50]}
       dry_run=False: {"deleted": N, "sample_names": [first 50]}
+
+    Implementation note: the previous SELECT-ids → DELETE-WHERE-IN
+    pattern was vulnerable to the psycopg 65535-parameter ceiling on
+    libraries with tag explosions. The live delete now runs a single
+    DELETE with the same NOT-IN predicate find_unused_tags uses, so
+    the row count scales without binding every id as a parameter.
+    Audit 2026-06-02.
     """
-    unused = find_unused_tags(session)
-    sample = [t.name for t in unused[:50]]
+    sample_rows = find_unused_tags(session, limit=50)
+    sample = [t.name for t in sample_rows]
+    used_via_image_tag = select(image_tag.c.tag_id).distinct()
+    used_via_series = select(SeriesPage.series_tag_id).where(
+        SeriesPage.series_tag_id.is_not(None)
+    ).distinct()
     if dry_run:
-        return {"count": len(unused), "sample_names": sample}
-    ids = [t.id for t in unused]
-    if ids:
-        session.execute(
-            Tag.__table__.delete().where(Tag.id.in_(ids))
-        )
-        session.commit()
-    return {"deleted": len(ids), "sample_names": sample}
+        count = session.execute(
+            select(func.count())
+            .select_from(Tag)
+            .where(Tag.id.not_in(used_via_image_tag))
+            .where(Tag.id.not_in(used_via_series))
+        ).scalar_one()
+        return {"count": count, "sample_names": sample}
+    result = session.execute(
+        Tag.__table__.delete()
+        .where(Tag.id.not_in(used_via_image_tag))
+        .where(Tag.id.not_in(used_via_series))
+    )
+    session.commit()
+    return {"deleted": result.rowcount or 0, "sample_names": sample}
 
 
 # Legacy tags FC no longer uses, in two shapes:
@@ -500,6 +521,9 @@ class ConfirmTokenMismatch(Exception):
 _VALID_RULES = ("transparency", "single_color")
 
 
+_AUDIT_GUARD_THRESHOLD_MINUTES = 135  # matches LIBRARY_AUDIT_STALL_THRESHOLD_MINUTES
+
+
 def start_audit_run(
     session: Session, *, rule: str, params: dict[str, Any],
 ) -> int:
@@ -507,11 +531,21 @@ def start_audit_run(
     scan_library_for_rule Celery task. Returns the new audit_id.
 
     Concurrent-runs guard: raises AuditAlreadyRunning if any audit_run
-    has status='running'. Operator must cancel or wait."""
+    has status='running' AND started recently. Audit 2026-06-02 made
+    the guard age-aware: a SIGKILL'd run leaves a row in 'running'
+    that the recovery sweep flips on its next pass (~5 min), but a
+    fresh start_audit_run between the SIGKILL and the sweep would
+    previously block forever. Past the threshold, treat the running
+    row as stale and let the sweep clean it up — the new run still
+    gets to start.
+    """
     if rule not in _VALID_RULES:
         raise ValueError(f"unknown rule {rule!r}; expected one of {_VALID_RULES}")
+    cutoff = datetime.now(UTC) - timedelta(minutes=_AUDIT_GUARD_THRESHOLD_MINUTES)
     existing = session.execute(
-        select(LibraryAuditRun.id).where(LibraryAuditRun.status == "running")
+        select(LibraryAuditRun.id)
+        .where(LibraryAuditRun.status == "running")
+        .where(LibraryAuditRun.started_at >= cutoff)
     ).scalar_one_or_none()
     if existing is not None:
         raise AuditAlreadyRunning(existing)

backend/app/services/credential_crypto.py

@@ -1,40 +1,82 @@
 """Fernet-based encryption for credential blobs.
 
 The key is a single 32-byte value (urlsafe-base64-encoded; what
-Fernet.generate_key produces) stored at a fixed path inside the
-images/data root. Created on first boot if absent; mode 0600. No KDF
-needed — the file contents are already maximum-entropy random bytes.
+Fernet.generate_key produces) stored at /images/secrets/credential_key.b64
+(mode 0600, parent dir 0700). The 2026-06-02 audit caught a silent
+key-regeneration path: on a partial disaster restore where the DB was
+restored but the secrets dir was lost, the old `_load_or_create_key`
+would mint a fresh key with no log, producing a working-looking system
+where every authenticated download failed AUTH_ERROR until the operator
+re-uploaded every credential by hand. Now the constructor refuses to
+auto-generate unless either:
 
-Operator backup procedure must include this file alongside the rest
-of /images/ — losing it makes existing encrypted_blob rows
-undecryptable (recovery = delete the rows and re-upload).
+  * the caller explicitly passes `bootstrap_ok=True` (tests, scripts), or
+  * the env var `CURATOR_BOOTSTRAP_NEW_KEY=1` is set (operator opt-in
+    during first-time setup).
+
+Otherwise it raises `MissingCredentialKey` so the app fails fast at
+startup and the operator can restore the key file from backup.
+
+Operator backup procedure must include /images/secrets/ alongside the
+rest of /images/ — losing the key file makes existing encrypted_blob
+rows undecryptable (recovery = delete the rows and re-upload).
 """
 
+import logging
 import os
 from pathlib import Path
 
 from cryptography.fernet import Fernet, InvalidToken
 
+log = logging.getLogger(__name__)
+
+_BOOTSTRAP_ENV_VAR = "CURATOR_BOOTSTRAP_NEW_KEY"
+
 
 class InvalidCredentialBlob(Exception):
     """Raised when decryption fails (wrong key, tampered blob, …)."""
 
 
+class MissingCredentialKey(Exception):
+    """The Fernet key file is missing AND the caller hasn't opted in to
+    generating a new one. Audit 2026-06-02: prevents silent key
+    regeneration on partial DB-restored / secrets-lost deployments.
+    Set CURATOR_BOOTSTRAP_NEW_KEY=1 for first-time setup, or restore the
+    key file from backup."""
+
+
 class CredentialCrypto:
     """Fernet encrypt/decrypt with an on-disk key file.
 
-    Instantiate with a path; the file is created on first access and
-    reused thereafter. Tests pass a tmp_path; production calls with
+    Instantiate with a path; the file is loaded if present, or created
+    if absent AND the caller has opted in (bootstrap_ok=True or
+    CURATOR_BOOTSTRAP_NEW_KEY=1 env var). Production sites:
     `IMAGES_ROOT / "secrets" / "credential_key.b64"`.
     """
 
-    def __init__(self, key_path: Path):
+    def __init__(self, key_path: Path, *, bootstrap_ok: bool | None = None):
         self._key_path = Path(key_path)
-        self._fernet = Fernet(self._load_or_create_key())
+        if bootstrap_ok is None:
+            bootstrap_ok = os.environ.get(_BOOTSTRAP_ENV_VAR) == "1"
+        self._fernet = Fernet(self._load_or_create_key(bootstrap_ok))
 
-    def _load_or_create_key(self) -> bytes:
+    def _load_or_create_key(self, bootstrap_ok: bool) -> bytes:
         if self._key_path.exists():
             return self._key_path.read_bytes()
+        if not bootstrap_ok:
+            raise MissingCredentialKey(
+                f"Fernet key file not found at {self._key_path}. "
+                f"For first-time setup, set {_BOOTSTRAP_ENV_VAR}=1. "
+                f"If this is a restored instance, restore the key file "
+                f"from backup — generating a new one would make every "
+                f"existing Credential row undecryptable."
+            )
+        log.warning(
+            "Generating NEW Fernet credential key at %s. Any existing "
+            "encrypted_blob rows in the DB will be undecryptable — "
+            "re-upload each credential after this completes.",
+            self._key_path,
+        )
         parent = self._key_path.parent
         parent.mkdir(parents=True, exist_ok=True)
         os.chmod(parent, 0o700)

backend/app/services/download_service.py

@@ -25,9 +25,17 @@ from sqlalchemy.orm import joinedload
 
 from ..models import Artist, DownloadEvent, Source
 from .credential_service import CredentialService
-from .gallery_dl import GalleryDLService, SourceConfig
+from .gallery_dl import (
+    BACKFILL_SKIP_VALUE,
+    BACKFILL_TIMEOUT_SECONDS,
+    TICK_SKIP_VALUE,
+    ErrorType,
+    GalleryDLService,
+    SourceConfig,
+)
 from .importer import Importer
 from .patreon_resolver import resolve_campaign_id
+from .platforms import auth_type_for
 from .scheduler_service import set_platform_cooldown
 
 log = logging.getLogger(__name__)
@@ -84,6 +92,18 @@ class DownloadService:
         ctx = setup
 
         source_config = SourceConfig.from_dict(ctx["config_overrides"] or {})
+        # alembic 0031 / plan #544: derive skip_value + timeout from the
+        # source's backfill_runs_remaining counter. When > 0, walk the full
+        # post history (skip: True + 1800s); when 0, exit gallery-dl after
+        # 20 contiguous archived items (skip: "exit:20" + the default
+        # 870s). Operator sets backfill via POST /api/sources/{id}/backfill.
+        backfill_remaining = ctx.get("backfill_runs_remaining", 0) or 0
+        if backfill_remaining > 0:
+            skip_value: bool | str = BACKFILL_SKIP_VALUE
+            source_config.timeout = BACKFILL_TIMEOUT_SECONDS
+        else:
+            skip_value = TICK_SKIP_VALUE
+
         effective_url = _effective_url(
             ctx["platform"], ctx["url"], ctx["config_overrides"] or {}
         )
@@ -95,6 +115,7 @@ class DownloadService:
             source_config=source_config,
             cookies_path=ctx["cookies_path"],
             auth_token=ctx["auth_token"],
+            skip_value=skip_value,
         )
 
         resolved_campaign_id: str | None = None
@@ -121,6 +142,7 @@ class DownloadService:
                         source_config=source_config,
                         cookies_path=ctx["cookies_path"],
                         auth_token=ctx["auth_token"],
+                        skip_value=skip_value,
                     )
 
         return await self._phase3_persist(
@@ -156,6 +178,13 @@ class DownloadService:
             return {"status": "in_flight", "event_id": existing.id}
         if existing and existing.status == "pending":
             existing.status = "running"
+            # Reset started_at on the pending→running transition so the
+            # recovery sweep (DOWNLOAD_STALL_THRESHOLD_MINUTES, 30 min)
+            # measures from real start, not from enqueue. On heavy-queue
+            # days a freshly-promoted event whose original started_at
+            # predated the cutoff would otherwise get swept mid-flight,
+            # racing phase3's commit. Audit 2026-06-02.
+            existing.started_at = datetime.now(UTC)
             await self.async_session.commit()
             event_id = existing.id
         else:
@@ -166,7 +195,12 @@ class DownloadService:
             event_id = ev.id
 
         artist = source.artist
-        if source.platform in ("discord", "pixiv"):
+        # Drive cookies-vs-token selection from the platform registry's
+        # auth_type so a new 7th token-platform automatically picks the
+        # right credential path. The hardcoded tuple here used to drift
+        # out of sync with credential_service's auth_type_for(). Audit
+        # 2026-06-02.
+        if auth_type_for(source.platform) == "token":
             cookies_path = None
             auth_token = await self.cred_service.get_token(source.platform)
         else:
@@ -185,6 +219,7 @@ class DownloadService:
             "config_overrides": dict(source.config_overrides or {}),
             "cookies_path": cookies_path,
             "auth_token": auth_token,
+            "backfill_runs_remaining": source.backfill_runs_remaining or 0,
         }
 
     async def _phase3_persist(
@@ -238,6 +273,40 @@ class DownloadService:
                     bytes_downloaded += path.stat().st_size  # noqa: ASYNC240
                 except OSError:
                     pass
+                # Enqueue thumbnail + ML for newly-attached images, matching
+                # the filesystem-import path (tasks/import_file.py:228-239).
+                # Importer.attach_in_place deliberately skips inline thumb
+                # generation to keep the import queue moving; the calling
+                # task is responsible for the enqueue. Operator-flagged
+                # 2026-06-01: without this, every downloaded image stayed
+                # at thumbnail_path=NULL until a periodic backfill swept
+                # it up, surfacing as broken-thumbnail tiles in the gallery
+                # for hours after a download landed. Lazy import to avoid
+                # circular-import risk between this service and the
+                # tasks/* modules that import it.
+                from ..tasks.ml import tag_and_embed
+                from ..tasks.thumbnail import generate_thumbnail
+                ids = list(result.member_image_ids)
+                if result.image_id is not None and result.image_id not in ids:
+                    ids.append(result.image_id)
+                for img_id in ids:
+                    generate_thumbnail.delay(img_id)
+                    tag_and_embed.delay(img_id)
+            elif result.status == "attached":
+                # Non-media or extracted archive captured as PostAttachment
+                # (FC-2d-iii). The canonical copy lives in the attachments
+                # store; the original download path is now redundant —
+                # mirror duplicate_hash cleanup so we don't keep two copies.
+                # Operator-flagged 2026-06-02 (Lustria OST zip).
+                import_summary["attached"] += 1
+                try:
+                    bytes_downloaded += path.stat().st_size  # noqa: ASYNC240
+                except OSError:
+                    pass
+                try:
+                    path.unlink(missing_ok=True)  # noqa: ASYNC240
+                except OSError:
+                    pass
             elif result.status == "skipped" and result.skip_reason and result.skip_reason.value in (
                 "duplicate_hash", "duplicate_phash",
             ):
@@ -246,6 +315,29 @@ class DownloadService:
                     path.unlink(missing_ok=True)  # noqa: ASYNC240
                 except OSError:
                     pass
+            elif result.status == "skipped":
+                # Soft skip (too_small, too_transparent, invalid_image) —
+                # the file just didn't qualify, not a download/ingest
+                # failure. Don't flag the run as error; the file stays
+                # on disk for operator inspection.
+                import_summary["skipped"] += 1
+            elif result.status == "failed":
+                # Hard failure (today only: archive probe crash/timeout).
+                # The original archive sits in /images/ as an orphan; the
+                # filesystem scanner would re-import and re-crash on the
+                # same file, so delete the source file and surface the
+                # error in import_summary. Audit 2026-06-02.
+                import_summary["errors"] += 1
+                try:
+                    path.unlink(missing_ok=True)  # noqa: ASYNC240
+                except OSError:
+                    pass
+            elif result.status == "refreshed":
+                # Currently unreachable from attach_in_place (the download
+                # path never runs in deep=True mode), but the importer's
+                # ImportResult contract enumerates it. Treat the same as
+                # 'attached' — work happened, no error. Audit 2026-06-02.
+                import_summary["attached"] += 1
             else:
                 import_summary["errors"] += 1
 
@@ -259,12 +351,21 @@ class DownloadService:
         run_stats["quarantined_count"] = dl_result.files_quarantined
         stderr_summary = self.gdl._extract_errors_warnings(dl_result.stderr)
 
-        status = "ok" if (dl_result.success and import_summary["errors"] == 0) else "error"
+        # Plan #544: PARTIAL means the run downloaded ≥1 file but the
+        # subprocess didn't finish in budget (typically wall-clock timeout
+        # mid-walk). Real work happened; the next tick continues via
+        # gallery-dl's archive. NOT a failure for status purposes.
+        if dl_result.success and import_summary["errors"] == 0:
+            status = "ok"
+        elif dl_result.error_type == ErrorType.PARTIAL and import_summary["errors"] == 0:
+            status = "ok"
+        else:
+            status = "error"
         ev.status = status
         ev.finished_at = datetime.now(UTC)
         ev.files_count = import_summary["attached"]
         ev.bytes_downloaded = bytes_downloaded
-        ev.error = dl_result.error_message if not dl_result.success else None
+        ev.error = dl_result.error_message if status == "error" else None
         ev.metadata_ = {
             "run_stats": run_stats,
             "error_type": dl_result.error_type.value if dl_result.error_type else None,
@@ -279,6 +380,33 @@ class DownloadService:
             source_id=ctx["source_id"], status=status, error_message=ev.error,
             error_type=dl_result.error_type.value if dl_result.error_type else None,
         )
+        # Plan #544: backfill lifecycle — auto-complete when a clean
+        # backfill run drained the queue (gallery-dl exited 0 + zero files
+        # downloaded means there was nothing to fetch); otherwise decrement
+        # the counter. Next tick falls back to tick mode once it hits 0.
+        #
+        # Audit 2026-06-02 gating: VALIDATION_FAILED also exits the
+        # subprocess with return_code=0 and files_downloaded=0 (every
+        # file was quarantined), which used to match the auto-complete
+        # predicate exactly — zeroing the operator's armed budget on
+        # the FIRST quarantine run instead of decrementing. Require
+        # dl_result.success + no error_type so only genuinely-empty
+        # successful runs drain the counter.
+        backfill_remaining = ctx.get("backfill_runs_remaining", 0) or 0
+        if backfill_remaining > 0:
+            src = (await self.async_session.execute(
+                select(Source).where(Source.id == ctx["source_id"])
+            )).scalar_one()
+            queue_drained = (
+                dl_result.success
+                and dl_result.error_type is None
+                and dl_result.return_code == 0
+                and dl_result.files_downloaded == 0
+            )
+            if queue_drained:
+                src.backfill_runs_remaining = 0
+            else:
+                src.backfill_runs_remaining = max(0, backfill_remaining - 1)
         await self.async_session.commit()
         return event_id
 
@@ -306,9 +434,15 @@ class DownloadService:
         if status == "ok":
             source.consecutive_failures = 0
             source.last_error = None
+            # alembic 0032 — clear the failure-class chip on success.
+            source.error_type = None
         elif status == "error":
             source.consecutive_failures = (source.consecutive_failures or 0) + 1
             source.last_error = error_message
+            # alembic 0032 — stamp the failure-class so FailingSourcesCard
+            # can render a colored chip and operators can bulk-triage
+            # by error class without opening Logs per row.
+            source.error_type = error_type
             if error_type == "rate_limited":
                 await set_platform_cooldown(self.async_session, source.platform)
         elif status == "skipped":

backend/app/services/extension_service.py

@@ -16,6 +16,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from ..models import Artist, Source
 from ..utils.slug import slugify
+from .source_service import NEW_SOURCE_BACKFILL_RUNS
 
 
 class UnknownPlatformError(Exception):
@@ -86,6 +87,67 @@ class ExtensionService:
             "created_artist": created_artist,
         }
 
+    async def probe(self, url: str) -> dict:
+        """Read-only resolution of a creator-page URL against the FC DB.
+        Returns one of:
+          - {state: 'unknown_platform'}            — URL didn't match any
+            platform's strict artist-page pattern
+          - {state: 'new',          platform, slug} — would create both
+            artist and source on quick-add
+          - {state: 'artist_match', platform, slug, artist}
+                                                   — artist exists, this
+            exact URL isn't a Source yet (collapses the sidecar-synthetic
+            case too — the synthetic anchor counts as an existing artist
+            row but not as a pollable Source for this URL)
+          - {state: 'source_match', platform, slug, artist, source}
+                                                   — exact (artist, platform,
+            url) Source already exists
+
+        Side-effect-free: two SELECTs at most.
+        """
+        try:
+            platform, raw_slug = self._derive(url)
+        except (UnknownPlatformError, InvalidUrlError):
+            return {"state": "unknown_platform"}
+
+        slug = slugify(raw_slug)
+        artist = (await self.session.execute(
+            select(Artist).where(Artist.slug == slug)
+        )).scalar_one_or_none()
+        if artist is None:
+            return {"state": "new", "platform": platform, "slug": slug}
+
+        artist_payload = {"id": artist.id, "name": artist.name, "slug": artist.slug}
+
+        source = (await self.session.execute(
+            select(Source).where(
+                Source.artist_id == artist.id,
+                Source.platform == platform,
+                Source.url == url,
+            )
+        )).scalar_one_or_none()
+        if source is None:
+            return {
+                "state": "artist_match",
+                "platform": platform,
+                "slug": slug,
+                "artist": artist_payload,
+            }
+
+        return {
+            "state": "source_match",
+            "platform": platform,
+            "slug": slug,
+            "artist": artist_payload,
+            "source": {
+                "id": source.id,
+                "artist_id": source.artist_id,
+                "platform": source.platform,
+                "url": source.url,
+                "enabled": source.enabled,
+            },
+        }
+
     def _derive(self, url: str) -> tuple[str, str]:
         if not isinstance(url, str) or not url.strip():
             raise InvalidUrlError("url is empty")
@@ -143,9 +205,16 @@ class ExtensionService:
             return existing, False
         sp = await self.session.begin_nested()
         try:
+            # New subscription sources arm a few backfill runs so the
+            # first ticks walk the full history (otherwise gallery-dl's
+            # exit:20 short-circuits before the archive is built).
+            # Mirrors SourceService.create — without it, Firefox quick-
+            # add on a creator with >20 unsynced posts would surface
+            # as "check failed" with no diagnosis. Audit 2026-06-02.
             src = Source(
                 artist_id=artist_id, platform=platform,
                 url=url, enabled=True,
+                backfill_runs_remaining=NEW_SOURCE_BACKFILL_RUNS,
             )
             self.session.add(src)
             await self.session.flush()

backend/app/services/gallery_dl.py

@@ -39,9 +39,40 @@ class ErrorType(StrEnum):
     HTTP_ERROR = "http_error"
     UNSUPPORTED_URL = "unsupported_url"
     VALIDATION_FAILED = "validation_failed"
+    # Run made real progress (downloaded ≥1 file) but did not finish in the
+    # subprocess budget. Distinct from UNKNOWN_ERROR — the downstream status
+    # mapping classifies this as "ok" because the next tick continues.
+    PARTIAL = "partial"
     UNKNOWN_ERROR = "unknown_error"
 
 
+# Tick mode (routine cron polls): skip ≤20 contiguous already-archived
+# items, then exit gallery-dl. Established subscription with zero new
+# content exits in ~30s of HEAD requests instead of walking to the bottom
+# of the post history (which can be hours for prolific creators). 20 (not
+# 5) is operator-set headroom against any edge case where paywalled or
+# otherwise-non-downloadable items might interleave with archived ones —
+# 20 contiguous HEADs is still negligible.
+TICK_SKIP_VALUE = "exit:20"
+
+# Backfill mode (operator-triggered deep scan): walk the full history.
+# Source.backfill_runs_remaining > 0 selects this mode; the longer
+# timeout below absorbs creators with thousands of posts.
+#
+# 30 seconds shy of Celery's hard `time_limit=1200` on download_source
+# (tasks/download.py:33). subprocess.run MUST raise TimeoutExpired
+# before Celery SIGKILLs the worker — same rationale as the tick
+# default at line 74. The audit (2026-06-02) caught this at 1800,
+# guaranteeing SIGKILL on any backfill that ran to its subprocess
+# budget: stdout/stderr lost, backfill_runs_remaining never
+# decrements, recovery sweep stamps generic "stranded" 30 min later.
+# Recreates the exact Knuxy #38275 failure mode the tick 870s default
+# was added to prevent. backfill_runs_remaining=3 still gives ~58
+# minutes of cumulative walk across three runs for prolific creators.
+BACKFILL_SKIP_VALUE = True
+BACKFILL_TIMEOUT_SECONDS = 1170
+
+
 # 30 seconds shy of download_source's Celery soft_time_limit (900s, see
 # tasks/download.py:32). subprocess.run MUST raise TimeoutExpired before
 # Celery raises SoftTimeLimitExceeded — otherwise Celery wins the race,
@@ -56,12 +87,19 @@ _DEFAULT_GDL_TIMEOUT_SECONDS = 870
 
 @dataclass
 class SourceConfig:
+    """Per-source overrides loaded from Source.config_overrides JSON.
+
+    Note: the gallery-dl `skip` value (tick vs backfill, see TICK_SKIP_VALUE /
+    BACKFILL_SKIP_VALUE) is NOT carried here — it derives from the
+    Source.backfill_runs_remaining column at the download_service layer
+    and is passed to _build_config_for_source as `skip_value`. Same for
+    the per-run subprocess timeout.
+    """
     content_types: list[str] = field(default_factory=lambda: ["all"])
     sleep: float | None = None
     sleep_request: float | None = None
     directory_pattern: str | None = None
     filename_pattern: str | None = None
-    skip_existing: bool = True
     save_metadata: bool = True
     timeout: int = _DEFAULT_GDL_TIMEOUT_SECONDS
 
@@ -73,7 +111,6 @@ class SourceConfig:
             sleep_request=data.get("sleep_request"),
             directory_pattern=data.get("directory_pattern"),
             filename_pattern=data.get("filename_pattern"),
-            skip_existing=data.get("skip_existing", True),
             save_metadata=data.get("save_metadata", True),
             timeout=data.get("timeout", _DEFAULT_GDL_TIMEOUT_SECONDS),
         )
@@ -231,6 +268,25 @@ class GalleryDLService:
                 "part-directory": str(self._config_dir / "temp"),
                 "retries": 3,
                 "timeout": 120.0,
+                # Forward Patreon as Referer/Origin to yt-dlp when it
+                # fetches video manifests. Operator-flagged 2026-06-01
+                # (DaferQ patreon): video posts hosted on Mux carry a JWT
+                # playback restriction that checks Referer/Origin on every
+                # request — not just the token signature. gallery-dl's
+                # HEAD probe to stream.mux.com returns 200 (the token is
+                # valid), but yt-dlp's actual GET-with-Range to fetch the
+                # m3u8 manifest 403s because yt-dlp sends its own default
+                # Referer, which Mux's policy rejects. Forcing the right
+                # headers fixes the headers-only case; Mux IP-range
+                # restrictions are unfixable from here.
+                "ytdl": {
+                    "raw-options": {
+                        "http_headers": {
+                            "Referer": "https://www.patreon.com/",
+                            "Origin": "https://www.patreon.com",
+                        },
+                    },
+                },
             },
             "output": {"progress": True},
         }
@@ -245,7 +301,18 @@ class GalleryDLService:
         platform: str,
         source_config: SourceConfig,
         artist_slug: str,
+        skip_value: bool | str = BACKFILL_SKIP_VALUE,
     ) -> dict:
+        """`skip_value` controls gallery-dl's archive-walk behavior:
+            - True (BACKFILL_SKIP_VALUE): walk full post history, skipping
+              archived items but continuing past them. Used in backfill mode.
+            - "exit:20" (TICK_SKIP_VALUE): exit gallery-dl after 20
+              contiguous archived items. Used in tick (routine catch-up)
+              mode for fast no-op syncs on creators with deep history.
+            - False: don't skip — redownload everything (not used in FC).
+        The caller (download_service) chooses based on
+        Source.backfill_runs_remaining.
+        """
         config = json.loads(json.dumps(self._get_default_config()))  # deep copy
 
         destination = str(self.images_root / artist_slug / platform)
@@ -255,7 +322,7 @@ class GalleryDLService:
             config["extractor"]["sleep"] = source_config.sleep
         if source_config.sleep_request is not None:
             config["extractor"]["sleep-request"] = source_config.sleep_request
-        config["extractor"]["skip"] = source_config.skip_existing
+        config["extractor"]["skip"] = skip_value
 
         if source_config.save_metadata:
             config["extractor"]["postprocessors"] = [
@@ -394,6 +461,22 @@ class GalleryDLService:
                     f"Subscription tier does not grant access to {count} post{'s' if count != 1 else ''}",
                 )
 
+        # Partial-success: the subprocess exited non-zero (typically because
+        # the wall-clock timeout fired mid-walk), but it had downloaded ≥1
+        # file by then and no source-level error category fired. The work
+        # the run DID do is real; gallery-dl's archive will pick up where
+        # it left off on the next tick. Mapped to status="ok" downstream
+        # (download_service.py) so this doesn't flag the source as
+        # "needs attention." Operator-flagged 2026-06-01 after a Knuxy
+        # patreon run downloaded hundreds of files then ran red on timeout.
+        files_downloaded = self._count_downloaded_files(stdout)
+        if not has_actual_error and files_downloaded > 0:
+            return (
+                ErrorType.PARTIAL,
+                f"Downloaded {files_downloaded} file{'s' if files_downloaded != 1 else ''}; "
+                "run did not complete in budget — next tick will continue",
+            )
+
         return ErrorType.UNKNOWN_ERROR, f"Unknown error (return code: {return_code})"
 
     def _count_downloaded_files(self, stdout: str) -> int:
@@ -545,6 +628,7 @@ class GalleryDLService:
         source_config: SourceConfig | None = None,
         cookies_path: str | None = None,
         auth_token: str | None = None,
+        skip_value: bool | str = BACKFILL_SKIP_VALUE,
     ) -> DownloadResult:
         start_time = time.time()
         started_at = datetime.now(UTC).isoformat()
@@ -552,7 +636,9 @@ class GalleryDLService:
         if source_config is None:
             source_config = SourceConfig()
 
-        config = self._build_config_for_source(platform, source_config, artist_slug)
+        config = self._build_config_for_source(
+            platform, source_config, artist_slug, skip_value=skip_value,
+        )
 
         if cookies_path:
             config["extractor"]["cookies"] = cookies_path
@@ -769,7 +855,13 @@ class GalleryDLService:
                 ),
             )
             etype, msg = self._categorize_error(proc.returncode, proc.stdout, proc.stderr)
-            if proc.returncode == 0 or etype == ErrorType.NO_NEW_CONTENT:
+            # TIER_LIMITED proves auth worked — gallery-dl reached the
+            # post, was told it's tier-gated. The download path treats
+            # this as success (line 712); verify must too, or operators
+            # rotate working cookies for no reason. Audit 2026-06-02.
+            if proc.returncode == 0 or etype in (
+                ErrorType.NO_NEW_CONTENT, ErrorType.TIER_LIMITED,
+            ):
                 return True, "Credentials valid — the feed authenticated."
             if etype == ErrorType.AUTH_ERROR:
                 return False, msg

backend/app/services/gallery_service.py

@@ -20,8 +20,9 @@ from datetime import datetime
 
 from sqlalchemy import Select, and_, exists, func, or_, select
 from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import aliased
 
-from ..models import Artist, ImageProvenance, ImageRecord, Post, Source, Tag
+from ..models import Artist, ImageProvenance, ImageRecord, Post, Tag
 from ..models.tag import image_tag
 
 CURSOR_SEPARATOR = "|"
@@ -133,10 +134,23 @@ def _provenance_clause(post_id, artist_id):
             ImageProvenance.post_id == post_id,
         )
     if artist_id is not None:
+        # Use Post.artist_id (alembic 0030 denormalized column) instead
+        # of joining through ImageProvenance.source_id → Source.artist_id.
+        # The denormalization is the always-present linkage; the source
+        # path now drops NULL-source provenance rows (filesystem-imported
+        # content) which would otherwise vanish from artist-filtered
+        # gallery views.
+        # ALIAS Post: the gallery query outer-joins Post on
+        # ImageRecord.primary_post_id (`_outer_join_primary_post`).
+        # SQLAlchemy would otherwise correlate a bare `Post` reference
+        # in this EXISTS subquery to that outer Post (which is NULL for
+        # images with no primary post), and the filter would silently
+        # match nothing.
+        post_inner = aliased(Post)
         return exists().where(
             ImageProvenance.image_record_id == ImageRecord.id,
-            ImageProvenance.source_id == Source.id,
-            Source.artist_id == artist_id,
+            ImageProvenance.post_id == post_inner.id,
+            post_inner.artist_id == artist_id,
         )
     return None
 

backend/app/services/importer.py

@@ -212,10 +212,10 @@ class Importer:
         which would lose the surrounding scan's progress — and re-run `stmt`
         (scalar_one) to return the row the other worker created.
 
-        Centralizes the pattern shared by _find_or_create_source,
-        _source_for_sidecar, and _find_or_create_post. The plain
-        SELECT-then-INSERT version lost races under the 5-min recovery sweep
-        (operator-flagged 2026-05-26)."""
+        Centralizes the pattern shared by _find_or_create_source and
+        _find_or_create_post. The plain SELECT-then-INSERT version lost
+        races under the 5-min recovery sweep (operator-flagged
+        2026-05-26)."""
         existing = self.session.execute(stmt).scalar_one_or_none()
         if existing is not None:
             return existing
@@ -258,47 +258,25 @@ class Importer:
             lambda: Source(artist_id=artist_id, platform=platform, url=url),
         )
 
-    def _source_for_sidecar(
-        self, *, artist_id: int, platform: str, artist_slug: str,
-    ) -> Source:
-        """Sidecar-import Source resolver. Used by both filesystem imports
-        and gallery-dl downloads (both write sidecar JSON, both flow through
-        _apply_sidecar / _capture_attachment).
+    def _lookup_source_for_sidecar(
+        self, *, artist_id: int, platform: str,
+    ) -> Source | None:
+        """Find the real subscription Source for (artist, platform), or
+        None if no subscription exists.
 
-        Source represents a subscription feed (one per artist+platform — the
-        URL polled by the FC-3 downloader). The filesystem importer used to
-        call _find_or_create_source(url=sd.post_url), creating one Source
-        row per post URL — 100s of junk Sources per artist, all with
-        enabled=True, polluting the artist detail page and tricking the
-        subscription checker into trying to poll patreon post URLs as feeds.
-        Operator-flagged 2026-05-26; consolidated via alembic 0022.
-
-        Resolution order: prefer a real (non-sidecar) Source over a
-        synthetic anchor. When alembic 0022 ran, it may have rewritten
-        per-post Sources into `sidecar:<platform>:<slug>` synthetic
-        anchors. If the operator later added the real subscription, both
-        rows now coexist. A naive `ORDER BY id ASC LIMIT 1` lookup would
-        pick the older synthetic and silently attach every gallery-dl
-        download to the wrong Source — operator-flagged 2026-05-31 after
-        the Subscriptions UI surfaced the phantom anchors. Pick the real
-        one when one exists; fall back to the synthetic; only create a
-        new synthetic when nothing exists for (artist, platform).
+        Pre-alembic-0030 this method would CREATE a synthetic
+        `sidecar:<platform>:<slug>` Source when no real one existed —
+        because `Post.source_id` was NOT NULL and the importer needed
+        something to attach Posts to. Alembic 0030 relaxed both
+        `Post.source_id` and `ImageProvenance.source_id` to nullable, so
+        synthetic anchors are obsolete; the importer now leaves
+        source_id as None when no subscription exists for the (artist,
+        platform). Operator-asked 2026-06-01: synthetic Sources had
+        leaked into the Subscriptions UI as phantom subscriptions and
+        the operator wanted the data model to truthfully say "this
+        content has no live subscription."
         """
-        real_stmt = (
-            select(Source)
-            .where(
-                Source.artist_id == artist_id,
-                Source.platform == platform,
-                ~Source.url.like("sidecar:%"),
-            )
-            .order_by(Source.id.asc())
-            .limit(1)
-        )
-        real = self.session.execute(real_stmt).scalar_one_or_none()
-        if real is not None:
-            return real
-
-        any_stmt = (
+        stmt = (
             select(Source)
             .where(
                 Source.artist_id == artist_id,
@@ -307,29 +285,37 @@ class Importer:
             .order_by(Source.id.asc())
             .limit(1)
         )
-        return self._get_or_create(
-            any_stmt,
-            lambda: Source(
-                artist_id=artist_id,
-                platform=platform,
-                url=f"sidecar:{platform}:{artist_slug}",
-                enabled=False,
-            ),
-        )
+        return self.session.execute(stmt).scalar_one_or_none()
 
     def _find_or_create_post(
-        self, *, source_id: int, external_post_id: str,
+        self, *, source_id: int | None, external_post_id: str,
+        artist_id: int,
     ) -> Post:
-        """Race-safe find-or-create on `post` keyed by
-        (source_id, external_post_id). Mirrors `_find_or_create_source`
-        — same savepoint + IntegrityError-recovery pattern."""
-        stmt = select(Post).where(
-            Post.source_id == source_id,
-            Post.external_post_id == external_post_id,
-        )
+        """Race-safe find-or-create on `post`. Keyed by
+        (source_id, external_post_id) when source_id is set — the
+        `uq_post_source_external_id` constraint guards. For NULL-source
+        posts the existence check matches on (artist_id, external_post_id),
+        which the partial unique index `uq_post_artist_external_id_null_source`
+        (alembic 0030) guards. Same savepoint + IntegrityError-recovery
+        pattern as the rest of the helpers."""
+        if source_id is not None:
+            stmt = select(Post).where(
+                Post.source_id == source_id,
+                Post.external_post_id == external_post_id,
+            )
+        else:
+            stmt = select(Post).where(
+                Post.source_id.is_(None),
+                Post.artist_id == artist_id,
+                Post.external_post_id == external_post_id,
+            )
         return self._get_or_create(
             stmt,
-            lambda: Post(source_id=source_id, external_post_id=external_post_id),
+            lambda: Post(
+                source_id=source_id,
+                artist_id=artist_id,
+                external_post_id=external_post_id,
+            ),
         )
 
     def import_one(self, source: Path) -> ImportResult:
@@ -370,12 +356,14 @@ class Importer:
             return None
         sd = parse_sidecar(data)
         platform = sd.platform or "unknown"
-        src = self._source_for_sidecar(
-            artist_id=artist.id, platform=platform, artist_slug=artist.slug,
+        src = self._lookup_source_for_sidecar(
+            artist_id=artist.id, platform=platform,
         )
         epid = sd.external_post_id or sc.stem
         return self._find_or_create_post(
-            source_id=src.id, external_post_id=epid,
+            source_id=src.id if src else None,
+            external_post_id=epid,
+            artist_id=artist.id,
         )
 
     def _capture_attachment(
@@ -386,10 +374,19 @@ class Importer:
             artist = self._resolve_artist(source)
             post = self._post_for_sidecar(source, artist)
         sha = _sha256_of(source)
-        existing = self.session.execute(
-            select(PostAttachment).where(PostAttachment.sha256 == sha)
-        ).scalar_one_or_none()
-        if existing is None:
+        select_existing = select(PostAttachment).where(PostAttachment.sha256 == sha)
+        existing = self.session.execute(select_existing).scalar_one_or_none()
+        if existing is not None:
+            self.session.commit()
+            return ImportResult(status="attached")
+        # Savepoint + IntegrityError recovery — PostAttachment.sha256 is
+        # UNIQUE, so two workers can both pass the SELECT and only the
+        # second INSERT fails. Without savepoint, the outer transaction
+        # poisons and the calling task crashes. attachments.store is
+        # sha-addressed so both workers race to write the same target
+        # path; shutil.copy2 + rename is idempotent. Audit 2026-06-02.
+        sp = self.session.begin_nested()
+        try:
             stored = self.attachments.store(source, sha)
             self.session.add(PostAttachment(
                 post_id=post.id if post else None,
@@ -402,10 +399,19 @@ class Importer:
                 size_bytes=source.stat().st_size,
             ))
             self.session.flush()
+            sp.commit()
+        except IntegrityError:
+            sp.rollback()
+            # Lost the race — the other worker's row is canonical.
+            self.session.execute(select_existing).scalar_one()
         self.session.commit()
         return ImportResult(status="attached")
 
-    def _import_archive(self, source: Path) -> ImportResult:
+    def _import_archive(
+        self, source: Path, *,
+        artist: Artist | None = None,
+        source_row: Source | None = None,
+    ) -> ImportResult:
         # Layer-3 isolation: bomb-size guard + integrity test in a
         # spawned child BEFORE extracting in this process. A
         # decompression bomb or a native-lib crash on a malformed
@@ -413,6 +419,14 @@ class Importer:
         # instead of OOMing/segfaulting the import worker. extract_archive
         # is already fail-soft for plain exceptions, so this only adds
         # the hard-crash protection.
+        #
+        # Audit 2026-06-02: optional artist/source_row kwargs let the
+        # download path thread its explicit subscription context
+        # through instead of having _resolve_artist re-derive from
+        # path-walk (which works by coincidence today because gallery-dl
+        # lays files out under /images/<artist_slug>/...). Filesystem
+        # import still calls bare _import_archive(source) and falls
+        # back to the path-walk derivation as before.
         probe = safe_probe.probe_archive(source)
         if not probe.ok:
             if probe.crashed:
@@ -424,24 +438,28 @@ class Importer:
             # still preserve the archive file itself as an attachment so
             # nothing silently vanishes, matching extract_archive's
             # fail-soft contract.
-            artist = self._resolve_artist(source)
-            post = self._post_for_sidecar(source, artist)
-            self._capture_attachment(source, post=post, artist=artist, resolved=True)
+            artist_use = artist if artist is not None else self._resolve_artist(source)
+            post = self._post_for_sidecar(source, artist_use)
+            self._capture_attachment(
+                source, post=post, artist=artist_use, resolved=True,
+            )
             return ImportResult(status="attached")
 
-        artist = self._resolve_artist(source)
-        post = self._post_for_sidecar(source, artist)
+        artist_use = artist if artist is not None else self._resolve_artist(source)
+        post = self._post_for_sidecar(source, artist_use)
         member_ids: list[int] = []
         with extract_archive(source) as members:
             for _name, member_path in members:
                 if not is_supported(member_path):
                     continue  # non-media preserved via the stored archive
-                res = self._import_media(member_path, source)
+                res = self._import_media(
+                    member_path, source, explicit_source=source_row,
+                )
                 if res.status in ("imported", "superseded") and res.image_id:
                     member_ids.append(res.image_id)
         # Preserve the archive itself (links to the same Post/Artist).
         self._capture_attachment(
-            source, post=post, artist=artist, resolved=True
+            source, post=post, artist=artist_use, resolved=True
         )
         if member_ids:
             return ImportResult(
@@ -451,7 +469,8 @@ class Importer:
         return ImportResult(status="attached")
 
     def _import_media(
-        self, source: Path, attribution_path: Path
+        self, source: Path, attribution_path: Path,
+        *, explicit_source: Source | None = None,
     ) -> ImportResult:
         """The media import pipeline (filters, dedup, copy, provenance).
 
@@ -598,7 +617,15 @@ class Importer:
             artist = self._attach_artist(record, artist_name)
 
         # Sidecar provenance (best-effort; never fails the import).
-        self._apply_sidecar(record, attribution_path, artist)
+        # explicit_source lets the FC-3c download path bind the new
+        # ImageProvenance row to its subscription Source instead of
+        # having _apply_sidecar re-derive via _lookup_source_for_sidecar.
+        # Audit 2026-06-02 — archive members extracted from a
+        # subscription-downloaded zip previously lost subscription
+        # linkage if the on-disk layout didn't match assumptions.
+        self._apply_sidecar(
+            record, attribution_path, artist, explicit_source=explicit_source,
+        )
 
         # Thumbnail is queued separately by the calling task; the importer
         # does not generate thumbnails inline so the import queue stays moving.
@@ -662,16 +689,36 @@ class Importer:
         them through. The sidecar JSON gallery-dl emits next to each
         downloaded file is read by `_apply_sidecar` via `find_sidecar`.
 
+        File-type dispatch parity with `import_one` (FC-2d-iii): zips,
+        PDFs, audio etc. become PostAttachments; archives are extracted.
+        Without this dispatch, gallery-dl-downloaded non-media bounced
+        back as `skipped+invalid_image`, which DownloadService counted
+        as an ingest error and flipped otherwise-successful runs to
+        status="error". Operator-flagged 2026-06-02 after a Lustria
+        patreon run with a 94MB OST zip went red despite 21 successful
+        image attaches.
+
         Caller's responsibilities after this returns:
           - duplicate_hash / duplicate_phash skip → delete the on-disk file
           - superseded → file stays where it is (now canonical)
           - imported → file stays where it is
+          - attached → the file's been copied into the attachments store;
+            caller may delete the on-disk original (mirrors duplicate_hash)
           - failed → file untouched; caller decides
         """
-        if not is_supported(path):
+        if path.suffix.lower() == ".json":
             return ImportResult(
                 status="skipped", skip_reason=SkipReason.invalid_image,
-                error=f"unsupported extension {path.suffix}",
+                error="sidecar json is metadata, not content",
+            )
+        if is_archive(path):
+            return self._import_archive(
+                path, artist=artist, source_row=source,
+            )
+        if not is_supported(path):
+            post = self._post_for_sidecar(path, artist) if artist else None
+            return self._capture_attachment(
+                path, post=post, artist=artist, resolved=True,
             )
 
         # Format / dimension / transparency filters (mirror _import_media).
@@ -743,7 +790,8 @@ class Importer:
                 if rel == "smaller_exists":
                     target = self.session.get(ImageRecord, match_id)
                     self._supersede(
-                        target, path, sha, phash, width, height, new_path=path
+                        target, path, sha, phash, width, height,
+                        new_path=path, artist=artist, source_row=source,
                     )
                     return ImportResult(status="superseded", image_id=match_id)
 
@@ -858,14 +906,15 @@ class Importer:
             src = explicit_source
         else:
             platform = sd.platform or "unknown"
-            src = self._source_for_sidecar(
+            src = self._lookup_source_for_sidecar(
                 artist_id=artist.id, platform=platform,
-                artist_slug=artist.slug,
             )
 
         epid = sd.external_post_id or sc.stem
         post = self._find_or_create_post(
-            source_id=src.id, external_post_id=epid,
+            source_id=src.id if src else None,
+            external_post_id=epid,
+            artist_id=artist.id,
         )
         if sd.post_url is not None:
             post.post_url = sd.post_url
@@ -901,7 +950,7 @@ class Importer:
                     ImageProvenance(
                         image_record_id=record.id,
                         post_id=post.id,
-                        source_id=src.id,
+                        source_id=src.id if src else None,
                         captured_metadata=sd.raw,
                     )
                 )
@@ -937,6 +986,8 @@ class Importer:
         self, existing: ImageRecord, source: Path, sha: str,
         phash: str, width: int | None, height: int | None,
         *, new_path: Path | None = None,
+        artist: Artist | None = None,
+        source_row: Source | None = None,
     ) -> None:
         """Replace `existing`'s file with the larger `source`, keeping the
         row id (so tags/series/curation stay attached). ML is cleared so
@@ -988,8 +1039,14 @@ class Importer:
         # _apply_sidecar resolves artist from the sidecar itself if the
         # existing row has none, and is internally guarded against
         # missing-or-malformed sidecars (silent return).
+        # Audit 2026-06-02: thread artist/source_row from the
+        # download-path caller (attach_in_place smaller_exists branch)
+        # so the supersede preserves explicit subscription linkage
+        # instead of re-deriving via path-walk.
         try:
-            self._apply_sidecar(existing, source, None)
+            self._apply_sidecar(
+                existing, source, artist, explicit_source=source_row,
+            )
         except Exception as exc:
             # Don't unwind the supersede DB swap if sidecar parsing
             # blows up unexpectedly — the file replacement is the

backend/app/services/ml/centroids.py

@@ -19,7 +19,6 @@ from ...models import (
     TagReferenceEmbedding,
 )
 from ...models.tag import image_tag
-from .embedder import MODEL_VERSION as SIGLIP_VERSION
 
 ELIGIBLE_KINDS = {
     TagKind.character,
@@ -46,6 +45,21 @@ class CentroidService:
             )
         ).scalar_one()
 
+    async def _model_version(self) -> str:
+        """Audit 2026-06-02: SigLIP model-version stamp comes from the
+        DB row, not the env constant. tag_and_embed (tasks/ml.py:110)
+        already reads from MLSettings.embedder_model_version, so by
+        sourcing centroid stamps + drift checks from the same row, we
+        eliminate the silent-drift case the audit flagged. env
+        SIGLIP_MODEL_VERSION still drives which model embedder.py
+        loads at runtime; the version stamp is purely the operator-
+        controlled identifier."""
+        return (
+            await self.session.execute(
+                select(MLSettings.embedder_model_version).where(MLSettings.id == 1)
+            )
+        ).scalar_one()
+
     async def recompute_for_tag(self, tag_id: int) -> bool:
         """Recompute one tag's centroid. Returns True if a centroid was
         written, False if skipped (ineligible kind or too few members)."""
@@ -69,19 +83,20 @@ class CentroidService:
             return False
 
         centroid = np.mean(np.stack(embeddings), axis=0).astype(np.float32)
+        model_version = await self._model_version()
 
         stmt = insert(TagReferenceEmbedding).values(
             tag_id=tag_id,
             embedding=centroid.tolist(),
             reference_count=len(embeddings),
-            model_version=SIGLIP_VERSION,
+            model_version=model_version,
         )
         stmt = stmt.on_conflict_do_update(
             index_elements=["tag_id"],
             set_={
                 "embedding": centroid.tolist(),
                 "reference_count": len(embeddings),
-                "model_version": SIGLIP_VERSION,
+                "model_version": model_version,
                 "updated_at": func.now(),
             },
         )
@@ -92,6 +107,7 @@ class CentroidService:
         """Tag ids whose centroid is stale: member count != reference_count,
         OR no centroid row, OR centroid built on a different SigLIP version.
         Only considers eligible-kind tags with embeddings present."""
+        current_model_version = await self._model_version()
         member_counts = (
             select(
                 image_tag.c.tag_id.label("tag_id"),
@@ -116,7 +132,7 @@ class CentroidService:
                     TagReferenceEmbedding.reference_count
                     != member_counts.c.members
                 )
-                | (TagReferenceEmbedding.model_version != SIGLIP_VERSION)
+                | (TagReferenceEmbedding.model_version != current_model_version)
             )
         )
         return list((await self.session.execute(stmt)).scalars().all())

backend/app/services/ml/suggestions.py

@@ -4,7 +4,7 @@ threshold-filtered, category-grouped, ranked suggestions for one image.
 
 from dataclasses import dataclass, field
 
-from sqlalchemy import select
+from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from ...models import (
@@ -16,6 +16,7 @@ from ...models import (
 from ...models.tag import image_tag
 from .aliases import AliasService
 from .centroids import CentroidService
+from .tag_name import normalize as normalize_tag_name
 from .tagger import SURFACED_CATEGORIES
 
 
@@ -48,11 +49,11 @@ class SuggestionService:
         ).scalar_one()
 
     def _threshold_for(self, s: MLSettings, category: str) -> float:
-        # 'artist' intentionally absent (FC-2d-vii-c) — falls through to
-        # the 1.01 "never surfaces" default like any unsurfaced category.
+        # 'artist' (FC-2d-vii-c) and 'copyright' (2026-06-01) retired;
+        # both fall through to the 1.01 "never surfaces" default like any
+        # unsurfaced category.
         return {
             "character": s.suggestion_threshold_character,
-            "copyright": s.suggestion_threshold_copyright,
             "general": s.suggestion_threshold_general,
         }.get(category, 1.01)
 
@@ -84,7 +85,12 @@ class SuggestionService:
         )
 
         # --- Camie predictions ---
-        candidates: list[tuple[str, str, float]] = []
+        # candidates carry (raw_name, display_name, category, confidence).
+        # raw_name = the booru-formatted vocab key, kept for alias_map
+        # lookup since alias rows are hand-curated against raw keys.
+        # display_name = normalize_tag_name(raw_name) — what the operator
+        # sees AND what gets written to tag.name on Accept.
+        candidates: list[tuple[str, str, str, float]] = []
         for name, p in predictions.items():
             category = p.get("category", "general")
             if category not in SURFACED_CATEGORIES:
@@ -92,10 +98,14 @@ class SuggestionService:
             conf = float(p.get("confidence", 0.0))
             if conf < self._threshold_for(settings, category):
                 continue
-            candidates.append((name, category, conf))
+            display = normalize_tag_name(name)
+            if display is None:
+                # emoticon / pure-punctuation vocab entry — drop entirely
+                continue
+            candidates.append((name, display, category, conf))
 
         alias_map = await self.aliases.resolve_many(
-            [(n, c) for n, c, _ in candidates]
+            [(raw, c) for raw, _disp, c, _conf in candidates]
         )
 
         merged: dict[object, Suggestion] = {}
@@ -116,8 +126,8 @@ class SuggestionService:
                     creates_new_tag=existing.creates_new_tag,
                 )
 
-        for name, category, conf in candidates:
-            canonical = alias_map.get((name, category))
+        for raw, display, category, conf in candidates:
+            canonical = alias_map.get((raw, category))
             if canonical is not None:
                 if canonical.id in applied or canonical.id in rejected:
                     continue
@@ -133,9 +143,17 @@ class SuggestionService:
                     ),
                 )
             else:
+                # Case-insensitive match on BOTH the raw camie key AND
+                # the normalized form — covers legacy underscore-named
+                # Tag rows accepted before normalization shipped, AND
+                # any tag the operator created with the human form.
                 existing_tag = (
                     await self.session.execute(
-                        select(Tag).where(Tag.name == name)
+                        select(Tag).where(
+                            func.lower(Tag.name).in_(
+                                [raw.lower(), display.lower()]
+                            )
+                        )
                     )
                 ).scalars().first()
                 if existing_tag is not None:
@@ -157,10 +175,10 @@ class SuggestionService:
                     )
                 else:
                     _merge(
-                        f"raw:{name}:{category}",
+                        f"raw:{display}:{category}",
                         Suggestion(
                             canonical_tag_id=None,
-                            display_name=name,
+                            display_name=display,
                             category=category,
                             score=conf,
                             source="tagger",

backend/app/services/ml/tag_name.py

@@ -0,0 +1,62 @@
+"""Camie vocabulary -> human-readable tag-name normalization.
+
+Camie v2's ~57k tag vocabulary is booru-derived and arrives as raw
+strings like `uchiha_sasuke_(naruto)`, `#unicus_(idolmaster)`,
+`1000-nen_ikiteru_(vocaloid)`, or `:/`. We want the operator to see
+"Uchiha Sasuke", "Unicus", "1000-Nen Ikiteru", or to never see the
+emoticon at all — and we want the same clean string to be what lands
+in `tag.name` when the suggestion is accepted, so Accept matches the
+existing-tag convention (`tag_service.find_or_create`).
+
+Rules (operator-approved 2026-06-03):
+  1. Strip leading junk chars (#, ., +, ;, ~, _, whitespace)
+  2. Drop trailing `_(disambiguator)` block(s), iteratively
+  3. Strip wrapping single/double quotes (after disambig removal so
+     `"foo_em_up"_(series)` -> `"foo_em_up"` -> `foo_em_up`)
+  4. Replace remaining `_` with space; collapse runs of whitespace
+  5. Add a space after any `:` (namespace:tag -> namespace: tag)
+  6. Preserve hyphens (booru hyphens often carry meaning)
+  7. Title-case each space-separated word (first character only —
+     apostrophes, digits, hyphens stay)
+  8. If no letters AND no digits remain, return None (drops emoticons
+     like `:/` or `^_^`; preserves bare digit tags like `2005`)
+  9. No surname/givenname swap — no reliable signal in the vocab
+"""
+
+import re
+
+_LEADING_JUNK = re.compile(r"^[#.+;~_\s]+")
+_TRAILING_DISAMBIG = re.compile(r"_\([^)]*\)\s*$")
+_MULTISPACE = re.compile(r"\s+")
+_COLON_NOSPACE = re.compile(r":(?=\S)")
+_HAS_ALPHANUMERIC = re.compile(r"[A-Za-z0-9]")
+
+
+def _strip_wrapping_quotes(s: str) -> str:
+    if len(s) >= 2 and s[0] == s[-1] and s[0] in ('"', "'"):
+        return s[1:-1]
+    return s
+
+
+def _title_word(w: str) -> str:
+    return w[:1].upper() + w[1:] if w else w
+
+
+def normalize(raw: str) -> str | None:
+    """Return the human-readable form of a raw Camie tag, or None if the
+    string is junk (emoticon, empty after stripping)."""
+    if not raw:
+        return None
+    s = _LEADING_JUNK.sub("", raw)
+    while True:
+        new = _TRAILING_DISAMBIG.sub("", s)
+        if new == s:
+            break
+        s = new
+    s = _strip_wrapping_quotes(s)
+    s = s.replace("_", " ")
+    s = _COLON_NOSPACE.sub(": ", s)
+    s = _MULTISPACE.sub(" ", s).strip()
+    if not s or not _HAS_ALPHANUMERIC.search(s):
+        return None
+    return " ".join(_title_word(w) for w in s.split(" "))

backend/app/services/ml/tagger.py

@@ -38,10 +38,13 @@ STORE_FLOOR = float(os.environ.get("TAGGER_STORE_FLOOR", "0.05"))
 
 # The categories FC-2b surfaces in the UI. Others (meta/rating/year) are
 # still stored but the suggestion service filters them out.
-# FC-2d-vii-c: 'artist' retired — artist identity is acquisition-derived
-# (image_record.artist_id), never ML-inferred. Raw predictions are still
-# stored at STORE_FLOOR but artist never surfaces.
-SURFACED_CATEGORIES = {"character", "copyright", "general"}
+# 'artist' retired in FC-2d-vii-c — artist identity is acquisition-derived
+# (image_record.artist_id), never ML-inferred. 'copyright' retired
+# 2026-06-01 — operator doesn't use the copyright tag-kind; fandom is
+# this app's franchise/series concept (per TagsView.vue's doc comment).
+# Raw predictions for both categories still get stored at STORE_FLOOR but
+# don't surface in suggestions.
+SURFACED_CATEGORIES = {"character", "general"}
 
 # ImageNet preprocessing constants (per Camie v2 onnx_inference.py).
 _IMAGENET_MEAN = np.array([0.485, 0.456, 0.406], dtype=np.float32)

backend/app/services/platforms/base.py

@@ -96,10 +96,12 @@ def str_field(v) -> str | None:
 # Shared gallery-dl invocation defaults. Embedded in each platform's
 # default_config (with platform-specific overrides) so per-platform
 # choices stay explicit.
+# Note: the gallery-dl `skip` value (tick "exit:20" vs backfill True) is
+# NOT here — it's derived from Source.backfill_runs_remaining at download
+# time. See plan #544 / gallery_dl.TICK_SKIP_VALUE,BACKFILL_SKIP_VALUE.
 GD_DEFAULTS = {
     "sleep": 3.0,
     "sleep_request": 1.5,
-    "skip_existing": True,
     "save_metadata": True,
     "timeout": 3600,
 }

backend/app/services/post_feed_service.py

@@ -69,13 +69,19 @@ class PostFeedService:
             raise ValueError("direction must be 'older' or 'newer'")
 
         sort_key = _sort_key()
+        # Artist via the denormalized Post.artist_id (alembic 0030);
+        # Source via LEFT JOIN since post.source_id can now be NULL for
+        # filesystem-imported posts with no live subscription. A
+        # platform= filter implicitly excludes NULL-source posts (they
+        # have no platform); an artist_id= filter still surfaces them
+        # because Post.artist_id is always set.
         stmt = (
             select(Post, Artist, Source)
-            .join(Source, Post.source_id == Source.id)
-            .join(Artist, Source.artist_id == Artist.id)
+            .join(Artist, Post.artist_id == Artist.id)
+            .outerjoin(Source, Post.source_id == Source.id)
         )
         if artist_id is not None:
-            stmt = stmt.where(Source.artist_id == artist_id)
+            stmt = stmt.where(Post.artist_id == artist_id)
         if platform is not None:
             stmt = stmt.where(Source.platform == platform)
         if cursor:
@@ -135,8 +141,8 @@ class PostFeedService:
         cursor for each end. Returns None if the post doesn't exist."""
         anchor = (await self.session.execute(
             select(Post, Artist, Source)
-            .join(Source, Post.source_id == Source.id)
-            .join(Artist, Source.artist_id == Artist.id)
+            .join(Artist, Post.artist_id == Artist.id)
+            .outerjoin(Source, Post.source_id == Source.id)
             .where(Post.id == post_id)
         )).one_or_none()
         if anchor is None:
@@ -168,8 +174,8 @@ class PostFeedService:
     async def get_post(self, post_id: int) -> dict | None:
         row = (await self.session.execute(
             select(Post, Artist, Source)
-            .join(Source, Post.source_id == Source.id)
-            .join(Artist, Source.artist_id == Artist.id)
+            .join(Artist, Post.artist_id == Artist.id)
+            .outerjoin(Source, Post.source_id == Source.id)
             .where(Post.id == post_id)
         )).one_or_none()
         if row is None:
@@ -260,7 +266,7 @@ class PostFeedService:
         return out
 
     def _to_dict(
-        self, post: Post, artist: Artist, source: Source,
+        self, post: Post, artist: Artist, source: Source | None,
         thumbs_map: dict, atts_map: dict,
     ) -> dict:
         plain_full = html_to_plain(post.description) if post.description else None
@@ -269,6 +275,9 @@ class PostFeedService:
         else:
             description_plain, truncated = truncate_at_word(plain_full, DESCRIPTION_LIMIT)
         thumbs_entry = thumbs_map.get(post.id, {"thumbs": [], "more": 0})
+        # `source` is null for filesystem-imported posts with no live
+        # subscription (alembic 0030). Frontend renders that as a
+        # "filesystem import" affordance instead of a platform chip.
         return {
             "id": post.id,
             "external_post_id": post.external_post_id,
@@ -279,7 +288,10 @@ class PostFeedService:
             "description_plain": description_plain,
             "description_truncated": truncated,
             "artist": {"id": artist.id, "name": artist.name, "slug": artist.slug},
-            "source": {"id": source.id, "platform": source.platform},
+            "source": (
+                {"id": source.id, "platform": source.platform}
+                if source is not None else None
+            ),
             "thumbnails": thumbs_entry["thumbs"],
             "thumbnails_more": thumbs_entry["more"],
             "attachments": atts_map.get(post.id, []),

backend/app/services/provenance_service.py

@@ -70,11 +70,15 @@ class ProvenanceService:
         rec = await self.session.get(ImageRecord, image_id)
         if rec is None:
             return None
+        # Artist via Post.artist_id (alembic 0030); Source via LEFT JOIN
+        # since both Post.source_id and ImageProvenance.source_id can be
+        # NULL for filesystem-imported content. Frontend renders source=
+        # null as "filesystem import."
         stmt = (
             select(ImageProvenance, Post, Source, Artist)
             .join(Post, Post.id == ImageProvenance.post_id)
-            .join(Source, Source.id == ImageProvenance.source_id)
-            .join(Artist, Artist.id == Source.artist_id)
+            .join(Artist, Artist.id == Post.artist_id)
+            .outerjoin(Source, Source.id == ImageProvenance.source_id)
             .where(ImageProvenance.image_record_id == image_id)
             .order_by(ImageProvenance.captured_at.asc(),
                       ImageProvenance.id.asc())
@@ -90,7 +94,7 @@ class ProvenanceService:
                     "captured_at": ip.captured_at.isoformat()
                     if ip.captured_at else None,
                     "post": _post_dict(post),
-                    "source": _source_dict(src),
+                    "source": _source_dict(src) if src is not None else None,
                     "artist": _artist_dict(art),
                 }
                 for ip, post, src, art in rows
@@ -99,10 +103,12 @@ class ProvenanceService:
         }
 
     async def for_post(self, post_id: int) -> dict | None:
+        # Same LEFT JOIN to Source — get_post must succeed for a
+        # NULL-source post.
         stmt = (
             select(Post, Source, Artist)
-            .join(Source, Source.id == Post.source_id)
-            .join(Artist, Artist.id == Source.artist_id)
+            .join(Artist, Artist.id == Post.artist_id)
+            .outerjoin(Source, Source.id == Post.source_id)
             .where(Post.id == post_id)
         )
         row = (await self.session.execute(stmt)).first()
@@ -111,7 +117,7 @@ class ProvenanceService:
         post, src, art = row
         return {
             "post": _post_dict(post),
-            "source": _source_dict(src),
+            "source": _source_dict(src) if src is not None else None,
             "artist": _artist_dict(art),
             "attachments": await self._attachments_for_posts([post.id]),
         }

backend/app/services/refetch_service.py

@@ -86,7 +86,7 @@ def attempt_refetch(
     if src is None:
         return {"status": "no_source"}
 
-    # Remove the bad copy so gallery-dl (skip_existing) re-fetches it on
+    # Remove the bad copy so gallery-dl's archive-skip re-fetches it on
     # the source re-check instead of skipping the still-present corrupt
     # file.
     try:

backend/app/services/source_service.py

@@ -59,9 +59,11 @@ class SourceRecord:
     config_overrides: dict | None
     last_checked_at: str | None
     last_error: str | None
+    error_type: str | None
     check_interval_override: int | None
     consecutive_failures: int
     next_check_at: str | None
+    backfill_runs_remaining: int
 
     def to_dict(self) -> dict:
         return {
@@ -75,9 +77,11 @@ class SourceRecord:
             "config_overrides": self.config_overrides,
             "last_checked_at": self.last_checked_at,
             "last_error": self.last_error,
+            "error_type": self.error_type,
             "check_interval_override": self.check_interval_override,
             "consecutive_failures": self.consecutive_failures,
             "next_check_at": self.next_check_at,
+            "backfill_runs_remaining": self.backfill_runs_remaining,
         }
 
 
@@ -85,6 +89,11 @@ class SourceRecord:
 
 _EDITABLE = {"enabled", "url", "config_overrides", "check_interval_override", "platform"}
 
+# Plan #544 follow-up: newly created enabled sources pre-arm backfill so
+# their first N polls walk gallery-dl's full post history with the longer
+# timeout (matches the manual "Deep scan" button's default).
+NEW_SOURCE_BACKFILL_RUNS = 3
+
 
 class SourceService:
     def __init__(self, session: AsyncSession):
@@ -137,9 +146,11 @@ class SourceService:
             config_overrides=source.config_overrides,
             last_checked_at=source.last_checked_at.isoformat() if source.last_checked_at else None,
             last_error=source.last_error,
+            error_type=source.error_type,
             check_interval_override=source.check_interval_override,
             consecutive_failures=source.consecutive_failures or 0,
             next_check_at=nxt.isoformat() if nxt else None,
+            backfill_runs_remaining=source.backfill_runs_remaining or 0,
         )
 
     async def _row_to_record(self, source: Source) -> SourceRecord:
@@ -157,7 +168,7 @@ class SourceService:
         if artist_id is not None:
             stmt = stmt.where(Source.artist_id == artist_id)
         if not include_synthetic:
-            # Filesystem-import sidecar anchors (importer._source_for_sidecar)
+            # Pre-alembic-0030 sidecar synthetic anchors
             # have url='sidecar:<platform>:<slug>' and exist only to give
             # imported Posts a NOT-NULL Source FK. They aren't pollable
             # feeds; the Subscriptions UI used to render them as phantom
@@ -201,10 +212,21 @@ class SourceService:
             select(func.count(Source.id)).where(Source.artist_id == artist_id)
         )).scalar_one()
 
+        # Plan #544 follow-up: a freshly added subscription has no archive
+        # yet, so the first few polls would walk the full post history in
+        # tick mode and trip exit:20 after ~20 contiguous archive hits —
+        # except there are none yet, so tick mode would walk forever and
+        # blow the wall-clock cap. Pre-arm backfill so the initial syncs
+        # use the longer timeout + skip:True walk. Tick mode resumes once
+        # the budget is spent or the queue drains.
+        # Disabled sources (incl. sidecar synthetics, url='sidecar:...')
+        # are never polled, so leave their counter at 0.
+        backfill_runs = NEW_SOURCE_BACKFILL_RUNS if enabled else 0
         source = Source(
             artist_id=artist_id, platform=platform, url=url,
             enabled=enabled, config_overrides=config_overrides,
             check_interval_override=check_interval_override,
+            backfill_runs_remaining=backfill_runs,
         )
         self.session.add(source)
         try:
@@ -264,6 +286,25 @@ class SourceService:
         await self.session.commit()
         return await self._row_to_record(source)
 
+    async def set_backfill_runs(
+        self, source_id: int, runs: int,
+    ) -> SourceRecord:
+        """Plan #544: arm a source for backfill mode. The next `runs`
+        download runs will use gallery-dl's full-walk config (skip: True
+        + 30-min timeout) instead of the catch-up default. Runs must be
+        1..10 — bigger is rejected to keep the operator from accidentally
+        setting a runaway budget."""
+        if not isinstance(runs, int) or runs < 1 or runs > 10:
+            raise ValueError("runs must be an integer in [1, 10]")
+        source = (await self.session.execute(
+            select(Source).where(Source.id == source_id)
+        )).scalar_one_or_none()
+        if source is None:
+            raise LookupError(f"source id={source_id} not found")
+        source.backfill_runs_remaining = runs
+        await self.session.commit()
+        return await self._row_to_record(source)
+
     async def delete(self, source_id: int) -> None:
         source = (await self.session.execute(
             select(Source).where(Source.id == source_id)

backend/app/services/tag_service.py

@@ -5,6 +5,7 @@ from dataclasses import dataclass
 
 from sqlalchemy import and_, case, exists, func, select, text, update
 from sqlalchemy.dialects.postgresql import insert as pg_insert
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from ..models import Tag, TagKind, image_tag
@@ -86,9 +87,12 @@ class TagService:
                     f"fandom_id {fandom_id} does not reference a fandom tag"
                 )
 
-        # Upsert via INSERT ... ON CONFLICT DO NOTHING. We can't use the
-        # uniqueness index name directly (it's a partial coalesce-based
-        # expression), so we re-select after insert.
+        # Audit 2026-06-02: race-safe upsert via savepoint +
+        # IntegrityError recovery. The partial uniqueness index on
+        # (name, kind, COALESCE(fandom_id, -1)) catches concurrent
+        # inserts; without the savepoint the outer transaction would
+        # poison and the calling request crashes. Mirrors
+        # importer._get_or_create.
         stmt = (
             select(Tag)
             .where(Tag.name == name)
@@ -101,10 +105,16 @@ class TagService:
         if existing:
             return existing
 
-        new_tag = Tag(name=name, kind=kind, fandom_id=fandom_id)
-        self.session.add(new_tag)
-        await self.session.flush()
-        return new_tag
+        sp = await self.session.begin_nested()
+        try:
+            new_tag = Tag(name=name, kind=kind, fandom_id=fandom_id)
+            self.session.add(new_tag)
+            await self.session.flush()
+            await sp.commit()
+            return new_tag
+        except IntegrityError:
+            await sp.rollback()
+            return (await self.session.execute(stmt)).scalar_one()
 
     async def autocomplete(
         self,

backend/app/tasks/backup.py

@@ -240,8 +240,11 @@ def prune_backups() -> dict:
 
     Returns {"db_deleted": N, "images_deleted": M, "files_unlinked": K}.
     Tagged rows (tag IS NOT NULL) are never pruned.
-    Status='running' / 'restoring' rows are never pruned (recovery
-    sweep from FC-3i handles those via task_run).
+    Status='running' / 'restoring' rows are never pruned — the
+    recover_stalled_backup_runs sweep flips truly-stuck ones to
+    'error' first. (Earlier docstring claimed the FC-3i TaskRun sweep
+    handled those, but TaskRun cleanup never touched BackupRun rows.
+    Audit 2026-06-02 added the dedicated sweep.)
     """
     SessionLocal = _sync_session_factory()
     counts = {"db_deleted": 0, "images_deleted": 0, "files_unlinked": 0}

backend/app/tasks/maintenance.py

@@ -7,14 +7,17 @@ from datetime import UTC, datetime, timedelta
 from pathlib import Path
 
 from PIL import Image
-from sqlalchemy import and_, delete, or_, select, update
+from sqlalchemy import Integer, and_, cast, delete, func, or_, select, update
 
 from ..celery_app import celery
 from ..models import (
+    BackupRun,
     DownloadEvent,
     ImageRecord,
+    ImportBatch,
     ImportSettings,
     ImportTask,
+    LibraryAuditRun,
     Source,
     TaskRun,
 )
@@ -55,6 +58,29 @@ FFPROBE_TIMEOUT_SECONDS = 10
 TASK_RUN_KEEP_OK_SECONDS = 24 * 3600       # 24 h
 TASK_RUN_KEEP_FAILURE_SECONDS = 7 * 24 * 3600  # 7 days
 
+# Audit 2026-06-02: per-entity recovery sweep thresholds. Each must be
+# > the entity's longest legitimate runtime (its task's time_limit + a
+# small buffer) so the sweep never flags in-flight work.
+#
+# Backups: images backup has time_limit=23400s (6.5h). 7h covers it
+# with a 30-min buffer; db backup at 12 min hard limit fits trivially.
+BACKUP_STALL_THRESHOLD_MINUTES = 7 * 60
+# Library audit: scan_library_for_rule has time_limit=7500s (2h5m).
+# 2h15m gives a 10-min buffer.
+LIBRARY_AUDIT_STALL_THRESHOLD_MINUTES = 135
+# Import batches finalize only after every child ImportTask hits a
+# terminal state. The recovery sweep targets the case where every
+# task is done but the batch never got its closing UPDATE
+# (orchestrator crashed at the wrong instant). 2h is well past any
+# realistic single-batch import.
+IMPORT_BATCH_STALL_THRESHOLD_MINUTES = 120
+
+# Retention windows (terminal rows older than these get deleted by
+# the daily prune sweeps). 30 days = operator-flagged "useful for
+# triage for a few weeks, then noise."
+LIBRARY_AUDIT_KEEP_DAYS = 30
+IMPORT_BATCH_KEEP_DAYS = 30
+
 # Overrides for recover_stalled_task_runs (the TaskRun 'running' sweep).
 # Tasks/queues that legitimately run longer than the default 5-min
 # threshold need their own larger value, else the sweep marks in-flight
@@ -69,9 +95,24 @@ TASK_RUN_KEEP_FAILURE_SECONDS = 7 * 24 * 3600  # 7 days
 #   files); time_limit=2100.
 QUEUE_STUCK_THRESHOLD_MINUTES: dict[str, int] = {
     "ml": 25,
+    # Audit 2026-06-02 — maintenance/scan queues run tasks that
+    # legitimately exceed the 5-min default (verify_integrity at 70m
+    # hard, scan_directory at 70m hard, apply_allowlist_tags /
+    # recompute_centroids / backfill_phash at 35m hard). 75 min lives
+    # above the longest of those and the per-task overrides below
+    # cover the outliers (backups, library audit).
+    "maintenance": 75,
+    "scan": 75,
 }
 TASK_STUCK_THRESHOLD_MINUTES: dict[str, int] = {
     "backend.app.tasks.import_file.import_archive_file": 40,
+    # Backup images runs hours, not minutes (6.5h hard limit). The
+    # task-name override beats the queue's 75-min default so a
+    # legitimately-running backup isn't flagged.
+    "backend.app.tasks.backup.backup_images_task": 420,
+    "backend.app.tasks.backup.restore_images_task": 420,
+    # Library audit scans the full library — 2h hard limit.
+    "backend.app.tasks.library_audit.scan_library_for_rule": 130,
 }
 
 
@@ -182,6 +223,11 @@ def recover_interrupted_tasks() -> int:
             .where(ImportTask.created_at < orphan_cutoff)
             .values(
                 status="failed",
+                # Without finished_at, cleanup_old_tasks (`WHERE
+                # finished_at < cutoff`) never reaps these rows —
+                # orphan-swept rows would become permanent table
+                # tenants. Audit 2026-06-02.
+                finished_at=now,
                 error=(
                     "orphan pending/queued swept by recover_interrupted_tasks "
                     "(scanner likely crashed mid-enqueue); retry via "
@@ -278,6 +324,14 @@ def recover_stalled_task_runs() -> int:
                     f"no completion signal received within {minutes} min"
                 ),
                 finished_at=now,
+                # Matches celery_signals.finalize's
+                # int((now - started_at).total_seconds() * 1000)
+                # — sweep-closed rows now carry duration like
+                # normally-finalized rows. Audit 2026-06-02.
+                duration_ms=cast(
+                    func.extract("epoch", now - TaskRun.started_at) * 1000,
+                    Integer,
+                ),
             )
         )
         for w in extra_where:
@@ -347,7 +401,12 @@ def prune_task_runs() -> dict:
         return {"ok_deleted": ok_deleted, "failures_deleted": fail_deleted}
 
 
-@celery.task(name="backend.app.tasks.maintenance.backfill_phash")
+@celery.task(
+    name="backend.app.tasks.maintenance.backfill_phash",
+    # Audit 2026-06-02 — keyset-paginated phash recompute over the whole
+    # library; legitimately runs >5 min on large libraries.
+    soft_time_limit=1800, time_limit=2100,
+)
 def backfill_phash() -> int:
     """Recompute phash for stored images that have none (imported before
     FC-2d-i+ii). Keyset-paginated by id (restart-safe), NULL-only fill,
@@ -425,7 +484,13 @@ def _verify_one(path: Path, expected_sha: str, mime: str, sha_fn) -> str:
         return "failed_verification"
 
 
-@celery.task(name="backend.app.tasks.maintenance.verify_integrity")
+@celery.task(
+    name="backend.app.tasks.maintenance.verify_integrity",
+    # Audit 2026-06-02 — full library sha256 + decode probe; on 100k-image
+    # libraries this runs an hour or more. Match the maintenance queue's
+    # recovery threshold (75 min) with 30s buffer below.
+    soft_time_limit=3600, time_limit=4200,
+)
 def verify_integrity() -> int:
     """Verify every ImageRecord file: sha256 recompute + decode/probe
     (PIL for images; ffprobe for videos). Writes integrity_status
@@ -521,6 +586,156 @@ def recover_stalled_download_events() -> int:
         return events_recovered
 
 
+@celery.task(name="backend.app.tasks.maintenance.recover_stalled_backup_runs")
+def recover_stalled_backup_runs() -> int:
+    """Flip BackupRun rows stuck in running/restoring past the hard limit
+    to error. Audit 2026-06-02.
+
+    prune_backups (FC-3h) used to claim the FC-3i task_run sweep handled
+    these — but that sweep only flips TaskRun rows, not the BackupRun
+    artifact rows. A SIGKILL'd backup left BackupRun stuck forever
+    (dashboard showed phantom in-flight backups, keep_last_n offset
+    arithmetic skewed because zombies sat outside the ok/error window).
+    """
+    SessionLocal = _sync_session_factory()
+    now = datetime.now(UTC)
+    cutoff = now - timedelta(minutes=BACKUP_STALL_THRESHOLD_MINUTES)
+    msg = (
+        f"stranded by recovery sweep (no terminal status after "
+        f"{BACKUP_STALL_THRESHOLD_MINUTES // 60}h)"
+    )
+    with SessionLocal() as session:
+        result = session.execute(
+            update(BackupRun)
+            .where(BackupRun.status.in_(["running", "restoring"]))
+            .where(BackupRun.started_at < cutoff)
+            .values(status="error", finished_at=now, error=msg)
+        )
+        session.commit()
+        recovered = result.rowcount or 0
+        if recovered:
+            log.info("recover_stalled_backup_runs: recovered %d rows", recovered)
+        return recovered
+
+
+@celery.task(name="backend.app.tasks.maintenance.recover_stalled_library_audit_runs")
+def recover_stalled_library_audit_runs() -> int:
+    """Flip LibraryAuditRun rows stuck in running past the hard limit
+    to error. Audit 2026-06-02.
+
+    LibraryAuditRun.status='running' was protected by an exclusive
+    guard in start_audit_run — a SIGKILL'd run would block all future
+    audits until manual DB surgery. (The guard is now age-aware, but
+    this sweep is what makes that work in practice.)
+    """
+    SessionLocal = _sync_session_factory()
+    now = datetime.now(UTC)
+    cutoff = now - timedelta(minutes=LIBRARY_AUDIT_STALL_THRESHOLD_MINUTES)
+    msg = (
+        f"stranded by recovery sweep (no terminal status after "
+        f"{LIBRARY_AUDIT_STALL_THRESHOLD_MINUTES} min)"
+    )
+    with SessionLocal() as session:
+        result = session.execute(
+            update(LibraryAuditRun)
+            .where(LibraryAuditRun.status == "running")
+            .where(LibraryAuditRun.started_at < cutoff)
+            .values(status="error", finished_at=now, error=msg)
+        )
+        session.commit()
+        recovered = result.rowcount or 0
+        if recovered:
+            log.info(
+                "recover_stalled_library_audit_runs: recovered %d rows", recovered,
+            )
+        return recovered
+
+
+@celery.task(name="backend.app.tasks.maintenance.recover_stalled_import_batches")
+def recover_stalled_import_batches() -> int:
+    """Finalize ImportBatch rows stuck in running past the hard limit
+    when NO outstanding ImportTask remains. Audit 2026-06-02.
+
+    A batch row finalizes only after every child task hits a terminal
+    state. The orphan case: scanner crashed between the last task's
+    completion and the batch's closing UPDATE. The
+    `/api/import/status` route then surfaces the batch as 'active'
+    indefinitely while `/api/system/stats` (which uses the same
+    EXISTS predicate we apply below) correctly returns null.
+    """
+    SessionLocal = _sync_session_factory()
+    now = datetime.now(UTC)
+    cutoff = now - timedelta(minutes=IMPORT_BATCH_STALL_THRESHOLD_MINUTES)
+    with SessionLocal() as session:
+        # Batches still 'running' past the cutoff whose tasks are all
+        # terminal — there's no outstanding work, so flip the batch
+        # too. Mirrors the EXISTS predicate the active-batch surfaces use.
+        result = session.execute(
+            update(ImportBatch)
+            .where(ImportBatch.status == "running")
+            .where(ImportBatch.started_at < cutoff)
+            .where(
+                ~select(ImportTask.id)
+                .where(
+                    ImportTask.batch_id == ImportBatch.id,
+                    ImportTask.status.in_(["pending", "queued", "processing"]),
+                )
+                .exists()
+            )
+            .values(status="complete", finished_at=now)
+        )
+        session.commit()
+        recovered = result.rowcount or 0
+        if recovered:
+            log.info(
+                "recover_stalled_import_batches: finalized %d zombie batches",
+                recovered,
+            )
+        return recovered
+
+
+@celery.task(name="backend.app.tasks.maintenance.prune_library_audit_runs")
+def prune_library_audit_runs() -> int:
+    """Daily retention: delete terminal LibraryAuditRun rows older than
+    LIBRARY_AUDIT_KEEP_DAYS. Never touches 'running'. Audit 2026-06-02.
+
+    Audit rows carry matched_ids JSONB blobs that can hold tens of
+    thousands of ids; without retention these accumulate.
+    """
+    SessionLocal = _sync_session_factory()
+    cutoff = datetime.now(UTC) - timedelta(days=LIBRARY_AUDIT_KEEP_DAYS)
+    with SessionLocal() as session:
+        result = session.execute(
+            delete(LibraryAuditRun)
+            .where(LibraryAuditRun.status.in_(["ready", "applied", "cancelled", "error"]))
+            .where(LibraryAuditRun.finished_at < cutoff)
+        )
+        session.commit()
+        return result.rowcount or 0
+
+
+@celery.task(name="backend.app.tasks.maintenance.prune_import_batches")
+def prune_import_batches() -> int:
+    """Daily retention: delete terminal ImportBatch rows older than
+    IMPORT_BATCH_KEEP_DAYS. Cascade-deletes child ImportTask rows via
+    the model relationship. Never touches 'running'. Audit 2026-06-02.
+    """
+    SessionLocal = _sync_session_factory()
+    cutoff = datetime.now(UTC) - timedelta(days=IMPORT_BATCH_KEEP_DAYS)
+    with SessionLocal() as session:
+        # ORM-level delete here (not Core delete) so the
+        # ImportBatch->tasks cascade fires; Core delete would skip it.
+        old_batches = session.execute(
+            select(ImportBatch)
+            .where(ImportBatch.status.in_(["complete", "cancelled"]))
+            .where(ImportBatch.finished_at < cutoff)
+        ).scalars().all()
+        for batch in old_batches:
+            session.delete(batch)
+        session.commit()
+        return len(old_batches)
+
+
 @celery.task(name="backend.app.tasks.maintenance.cleanup_old_download_events")
 def cleanup_old_download_events() -> int:
     """FC-3d: delete terminal DownloadEvent rows older than the configured

backend/app/tasks/ml.py

@@ -212,7 +212,14 @@ def backfill(self) -> int:
     return enqueued
 
 
-@celery.task(name="backend.app.tasks.ml.apply_allowlist_tags", bind=True)
+@celery.task(
+    name="backend.app.tasks.ml.apply_allowlist_tags",
+    bind=True,
+    # Audit 2026-06-02 — the full-sweep mode (neither tag_id nor image_id)
+    # is O(images × allowlist) and legitimately runs >5 min on large
+    # libraries. Cap matches the maintenance queue's recovery threshold.
+    soft_time_limit=1800, time_limit=2100,
+)
 def apply_allowlist_tags(self, tag_id: int | None = None,
                          image_id: int | None = None) -> int:
     """Retroactively apply allowlisted tags.
@@ -341,7 +348,13 @@ def recompute_centroid(self, tag_id: int) -> bool:
     return asyncio.run(_run())
 
 
-@celery.task(name="backend.app.tasks.ml.recompute_centroids", bind=True)
+@celery.task(
+    name="backend.app.tasks.ml.recompute_centroids",
+    bind=True,
+    # Audit 2026-06-02 — drifted-centroid rebuild over potentially
+    # hundreds of tags.
+    soft_time_limit=1800, time_limit=2100,
+)
 def recompute_centroids(self) -> int:
     """Daily: find drifted centroids, enqueue recompute_centroid for each."""
     import asyncio

backend/app/tasks/scan.py

@@ -35,7 +35,15 @@ def _iter_import_files(import_root: Path):
         yield entry
 
 
-@celery.task(name="backend.app.tasks.scan.scan_directory", bind=True)
+@celery.task(
+    name="backend.app.tasks.scan.scan_directory",
+    bind=True,
+    # Audit 2026-06-02 — large libraries make the scan legitimately long.
+    # Hard cap at 70 min so the corresponding QUEUE_STUCK_THRESHOLD_MINUTES
+    # ("scan") of 75 min always wins; soft limit gives the task a clean
+    # exit window before SIGKILL.
+    soft_time_limit=3600, time_limit=4200,
+)
 def scan_directory(self, triggered_by: str = "manual",
                    mode: str = "quick") -> int:
     """Walks the import root and creates ImportTasks. `mode` is 'quick'

backend/app/tasks/thumbnail.py

@@ -20,14 +20,32 @@ IMAGES_ROOT = Path("/images")
 THUMB_MAGIC_JPEG = b"\xff\xd8\xff"
 THUMB_MAGIC_PNG = b"\x89PNG\r\n\x1a\n"
 
+# Minimum file size for a thumbnail to count as valid. Anything smaller
+# is almost certainly truncated/corrupt — a legitimate 400×400 JPEG@85
+# bottoms out around 2KB even on a solid-color image; 400×400 PNG starts
+# around 1KB. 256 bytes is well below any real thumbnail and well above
+# header-only corrupt files (~8-12 bytes). Operator-flagged 2026-06-01:
+# header-only corrupt files were silently passing the magic-byte check
+# and backfill counted them as "ok" — so broken-image tiles in the UI
+# never got regenerated even after running backfill.
+MIN_THUMB_BYTES = 256
+
 
 def _thumb_is_valid(path: Path) -> bool:
-    """Return True iff `path` exists and starts with a JPEG or PNG magic header.
+    """Return True iff `path` exists, starts with a JPEG or PNG magic
+    header, AND is at least MIN_THUMB_BYTES on disk.
 
-    The on-disk thumbnail format is set by services/thumbnailer.py — JPEG for
-    opaque sources, PNG for alpha sources. Anything else (missing file, OSError,
-    truncated, wrong magic) is invalid.
+    The on-disk thumbnail format is set by services/thumbnailer.py — JPEG
+    for opaque sources, PNG for alpha sources. Anything else (missing
+    file, OSError, truncated below the size floor, wrong magic) is
+    invalid and gets re-enqueued.
     """
+    try:
+        size = path.stat().st_size
+    except OSError:
+        return False
+    if size < MIN_THUMB_BYTES:
+        return False
     try:
         with path.open("rb") as f:
             head = f.read(12)
@@ -42,6 +60,59 @@ def _thumb_is_valid(path: Path) -> bool:
     return False
 
 
+def _run_backfill_scan() -> dict:
+    """Synchronous scan logic shared by the Celery task and the API
+    endpoint. Returns {enqueued, ok, regenerated, scanned}.
+
+    Operator-flagged 2026-06-01: the original task was fire-and-forget,
+    so the admin UI couldn't show what backfill actually found —
+    operator saw \"Enqueued.\" with no counts and assumed nothing was
+    happening. Now the API runs this synchronously and returns the
+    real numbers; the periodic Celery task wraps it too."""
+    from sqlalchemy import select, update
+
+    SessionLocal = _sync_session_factory()
+    enqueued = 0
+    ok = 0
+    regenerated = 0
+    scanned = 0
+    last_id = 0
+    with SessionLocal() as session:
+        while True:
+            rows = session.execute(
+                select(ImageRecord.id, ImageRecord.thumbnail_path)
+                .where(ImageRecord.id > last_id)
+                .order_by(ImageRecord.id.asc())
+                .limit(500)
+            ).all()
+            if not rows:
+                break
+            scanned += len(rows)
+            for image_id, thumb_path in rows:
+                if thumb_path is None:
+                    generate_thumbnail.delay(image_id)
+                    enqueued += 1
+                elif _thumb_is_valid(Path(thumb_path)):
+                    ok += 1
+                else:
+                    session.execute(
+                        update(ImageRecord)
+                        .where(ImageRecord.id == image_id)
+                        .values(thumbnail_path=None)
+                    )
+                    generate_thumbnail.delay(image_id)
+                    enqueued += 1
+                    regenerated += 1
+            session.commit()
+            last_id = rows[-1][0]
+    return {
+        "scanned": scanned,
+        "enqueued": enqueued,
+        "ok": ok,
+        "regenerated": regenerated,
+    }
+
+
 @celery.task(
     name="backend.app.tasks.thumbnail.generate_thumbnail",
     bind=True,
@@ -84,48 +155,15 @@ def backfill_thumbnails(self) -> dict:
     """Scan ImageRecord and enqueue generate_thumbnail for rows whose
     thumbnail is missing, gone from disk, or has wrong magic bytes.
 
-    Keyset paginates by id ASC, page size 500. NULLs out thumbnail_path for
-    rows that point at a missing or corrupt file before enqueueing — keeps
-    the DB self-consistent on partial runs and makes re-runs safe.
+    Keyset paginates by id ASC, page size 500. NULLs out thumbnail_path
+    for rows that point at a missing or corrupt file before enqueueing —
+    keeps the DB self-consistent on partial runs and makes re-runs safe.
 
-    Returns {"enqueued": N, "ok": M, "regenerated": K} where:
-      - enqueued = total generate_thumbnail.delay() calls
-      - ok       = rows whose existing thumbnail file is valid (skipped)
-      - regenerated = subset of enqueued that had a non-NULL thumbnail_path
-                      cleared (i.e. missing + corrupt)
+    Returns {scanned, enqueued, ok, regenerated} where:
+      - scanned    = total rows examined
+      - enqueued   = total generate_thumbnail.delay() calls
+      - ok         = rows whose existing thumbnail file is valid (skipped)
+      - regenerated = subset of enqueued that had a non-NULL
+                      thumbnail_path cleared (i.e. missing + corrupt)
     """
-    from sqlalchemy import select, update
-
-    SessionLocal = _sync_session_factory()
-    enqueued = 0
-    ok = 0
-    regenerated = 0
-    last_id = 0
-    with SessionLocal() as session:
-        while True:
-            rows = session.execute(
-                select(ImageRecord.id, ImageRecord.thumbnail_path)
-                .where(ImageRecord.id > last_id)
-                .order_by(ImageRecord.id.asc())
-                .limit(500)
-            ).all()
-            if not rows:
-                break
-            for image_id, thumb_path in rows:
-                if thumb_path is None:
-                    generate_thumbnail.delay(image_id)
-                    enqueued += 1
-                elif _thumb_is_valid(Path(thumb_path)):
-                    ok += 1
-                else:
-                    session.execute(
-                        update(ImageRecord)
-                        .where(ImageRecord.id == image_id)
-                        .values(thumbnail_path=None)
-                    )
-                    generate_thumbnail.delay(image_id)
-                    enqueued += 1
-                    regenerated += 1
-            session.commit()
-            last_id = rows[-1][0]
-    return {"enqueued": enqueued, "ok": ok, "regenerated": regenerated}
+    return _run_backfill_scan()

extension/background/background.js

@@ -194,9 +194,20 @@ browser.runtime.onMessage.addListener(async (msg) => {
         if (platform.authType === 'cookies') {
           const cookies = await extractCookiesForPlatform(key);
           if (cookies.length === 0) return { error: 'No cookies found — log in first.' };
+          // Verify the captured cookies are actually live BEFORE
+          // uploading. Skips upload on confirmed-stale sessions so we
+          // don't overwrite FC-side credentials with garbage. Platforms
+          // without a verify config (verify.ok === null) fall through
+          // to upload as before.
+          const v = await verifyCookiesForPlatform(key);
+          if (v.ok === false) {
+            return {
+              error: `Captured ${cookies.length} ${platform.name} cookies but they don't appear authenticated (${v.reason}). Log in again in this browser, then retry.`,
+            };
+          }
           const data = toNetscapeFormat(cookies);
           await api.uploadCredentials(key, 'cookies', data);
-          return { success: true, cookieCount: cookies.length };
+          return { success: true, cookieCount: cookies.length, verified: v.ok === true };
         }
         if (key === 'discord') {
           if (!discordToken) return { error: 'Open discord.com to capture a token first.' };
@@ -229,8 +240,13 @@ browser.runtime.onMessage.addListener(async (msg) => {
             results[key] = { skipped: true, reason: 'no cookies' };
             continue;
           }
+          const v = await verifyCookiesForPlatform(key);
+          if (v.ok === false) {
+            results[key] = { error: `verify failed: ${v.reason}` };
+            continue;
+          }
           await api.uploadCredentials(key, 'cookies', toNetscapeFormat(cookies));
-          results[key] = { success: true, cookieCount: cookies.length };
+          results[key] = { success: true, cookieCount: cookies.length, verified: v.ok === true };
         } catch (e) {
           results[key] = { error: e.message };
         }
@@ -259,6 +275,29 @@ browser.runtime.onMessage.addListener(async (msg) => {
         return { error: e.message };
       }
 
+    case 'PROBE_SOURCE':
+      try {
+        return await api.probeSource(msg.url);
+      } catch (e) {
+        return { error: e.message };
+      }
+
+    case 'OPEN_ARTIST_PAGE': {
+      // apiUrl is configured with the /api suffix (see
+      // options/options.html placeholder); the SPA artist route is
+      // /artist/:slug, served from the same origin. Strip /api so the
+      // browser-level URL hits the Vue router, not the JSON API.
+      const base = (api.baseUrl || '').replace(/\/+$/, '').replace(/\/api$/, '');
+      const slug = encodeURIComponent(msg.slug || '');
+      if (!base || !slug) return { error: 'apiUrl or slug missing' };
+      try {
+        await browser.tabs.create({ url: `${base}/artist/${slug}` });
+        return { success: true };
+      } catch (e) {
+        return { error: e.message };
+      }
+    }
+
     default:
       return { error: `Unknown message type: ${msg.type}` };
   }

extension/content/content-script.css

@@ -5,11 +5,26 @@
   background: rgb(20, 23, 26); color: rgb(244, 186, 122);
   font: 500 14px/1.2 system-ui, sans-serif;
   box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4); cursor: pointer;
-  transition: transform 100ms ease;
+  transition: transform 100ms ease, background 150ms ease, color 150ms ease;
 }
 .fc-add-source-btn:hover { transform: translateY(-1px); }
 .fc-add-source-btn:disabled { opacity: 0.6; cursor: wait; }
 
+/* state colors map to the FC palette: parchment-on-slate base,
+   accent-orange for new, sage for already-subscribed, amber-warning for
+   artist-exists-but-source-missing. All readable on the dark base. */
+.fc-add-source-btn--new {
+  background: rgb(20, 23, 26); color: rgb(244, 186, 122);
+}
+.fc-add-source-btn--artist-match {
+  background: rgb(28, 23, 16); color: rgb(255, 200, 120);
+  border: 1px solid rgb(180, 130, 60);
+}
+.fc-add-source-btn--source-match {
+  background: rgb(18, 28, 20); color: rgb(140, 220, 160);
+  border: 1px solid rgb(80, 160, 100);
+}
+
 .fc-toast {
   all: revert;
   position: fixed; bottom: 84px; right: 24px; z-index: 2147483647;

extension/content/content-script.js

@@ -2,6 +2,10 @@
   if (window.__fc_addsource_injected) return;
   window.__fc_addsource_injected = true;
 
+  // Cached probe result for the current URL so click-handlers know which
+  // action to dispatch without round-tripping again.
+  let currentProbe = null;
+
   evaluate();
 
   const reEval = () => evaluate();
@@ -9,38 +13,116 @@
   const origPush = history.pushState;
   history.pushState = function () { origPush.apply(this, arguments); reEval(); };
 
-  function evaluate() {
-    const platform = getPlatformFromUrl(window.location.href);
-    const onArtist = platform && isArtistPage(window.location.href, platform);
-    let btn = document.getElementById('fc-add-source-btn');
-    if (onArtist && !btn) injectButton();
-    else if (!onArtist && btn) btn.remove();
+  async function evaluate() {
+    const url = window.location.href;
+    const platform = getPlatformFromUrl(url);
+    const onArtist = platform && isArtistPage(url, platform);
+    const btn = document.getElementById('fc-add-source-btn');
+    if (!onArtist) {
+      if (btn) btn.remove();
+      currentProbe = null;
+      return;
+    }
+    // On artist pages, ask the backend what state the URL is in BEFORE
+    // injecting the button — so the chip can render the right state on
+    // first paint instead of flashing the generic "Add" copy and
+    // updating afterwards.
+    let probe;
+    try {
+      probe = await browser.runtime.sendMessage({ type: 'PROBE_SOURCE', url });
+    } catch (e) {
+      probe = { error: e?.message || 'probe failed' };
+    }
+    currentProbe = probe;
+    if (probe?.state === 'unknown_platform') {
+      if (btn) btn.remove();
+      return;
+    }
+    renderButton(probe);
   }
 
-  function injectButton() {
-    const btn = document.createElement('button');
-    btn.id = 'fc-add-source-btn';
+  function renderButton(probe) {
+    let btn = document.getElementById('fc-add-source-btn');
+    if (!btn) {
+      btn = document.createElement('button');
+      btn.id = 'fc-add-source-btn';
+      btn.addEventListener('click', onClick);
+      document.body.appendChild(btn);
+    }
+    // Reset state classes so re-renders (SPA navigation) don't stack.
     btn.className = 'fc-add-source-btn';
-    btn.textContent = '+ Add to FabledCurator';
-    btn.addEventListener('click', onClick);
-    document.body.appendChild(btn);
+    btn.classList.add(`fc-add-source-btn--${stateModifier(probe)}`);
+    btn.textContent = labelFor(probe);
+    btn.disabled = false;
+  }
+
+  function stateModifier(probe) {
+    if (!probe || probe.error) return 'new';
+    return ({
+      source_match: 'source-match',
+      artist_match: 'artist-match',
+      new: 'new',
+    })[probe.state] || 'new';
+  }
+
+  function labelFor(probe) {
+    if (!probe || probe.error) return '+ Add to FabledCurator';
+    const platformName = platformDisplayName(probe.platform);
+    const artistName = probe.artist?.name;
+    switch (probe.state) {
+      case 'source_match':
+        return `✓ In FabledCurator · ${platformName}`;
+      case 'artist_match':
+        return `+ Add ${platformName} source to ${artistName || 'artist'}`;
+      case 'new':
+      default:
+        return '+ Add to FabledCurator';
+    }
+  }
+
+  function platformDisplayName(key) {
+    return PLATFORMS[key]?.name || key || '';
   }
 
   async function onClick() {
     const btn = document.getElementById('fc-add-source-btn');
+    if (!btn) return;
     btn.disabled = true;
     const original = btn.textContent;
+    const probe = currentProbe;
+
+    if (probe?.state === 'source_match') {
+      btn.textContent = 'Opening…';
+      try {
+        const r = await browser.runtime.sendMessage({
+          type: 'OPEN_ARTIST_PAGE',
+          slug: probe.artist?.slug,
+        });
+        if (r?.error) showToast(`Error: ${r.error}`, 'error');
+      } catch (e) {
+        showToast(`Error: ${e.message}`, 'error');
+      } finally {
+        btn.disabled = false;
+        btn.textContent = original;
+      }
+      return;
+    }
+
     btn.textContent = 'Adding…';
     try {
       const r = await browser.runtime.sendMessage({
         type: 'ADD_AS_SOURCE',
         url: window.location.href,
       });
-      if (r.error) {
+      if (r?.error) {
         showToast(`Error: ${r.error}`, 'error');
       } else {
         const verb = r.created_source ? 'Added' : 'Already a source for';
         showToast(`${verb} ${r.artist?.name || 'artist'} (${r.source?.platform || ''})`, 'success');
+        // Re-probe so the chip flips green without waiting for the next
+        // navigation.
+        evaluate();
+        return;
       }
     } catch (e) {
       showToast(`Error: ${e.message}`, 'error');

extension/lib/api.js

@@ -83,6 +83,12 @@ class FabledCuratorAPI {
   quickAddSource(url) {
     return this.request('POST', '/extension/quick-add-source', { url });
   }
+  probeSource(url) {
+    // Read-only existence check. Drives the content-script chip's
+    // color/copy BEFORE the operator clicks Add.
+    const qs = new URLSearchParams({ url }).toString();
+    return this.request('GET', `/extension/probe?${qs}`);
+  }
 
   // Connection test = the cheapest read with auth.
   testConnection() {

extension/lib/cookies.js

@@ -76,3 +76,38 @@ async function getCookieCount(platformKey) {
     return 0;
   }
 }
+
+/**
+ * Verify cookies are live by hitting an authenticated endpoint with the
+ * browser's current cookie jar. Returns:
+ *   { ok: true,  status }      — verified
+ *   { ok: false, status, reason } — endpoint said we're not logged in
+ *   { ok: null,  reason }      — no verify config for this platform; caller
+ *                                should treat as "verify not available,
+ *                                proceed with upload"
+ *
+ * Implementation note: extensions with `host_permissions` for the target
+ * domain get the user's cookies auto-attached to fetch() — same set
+ * gallery-dl will later use on the backend.
+ */
+async function verifyCookiesForPlatform(platformKey) {
+  const platform = PLATFORMS[platformKey];
+  if (!platform) return { ok: false, reason: `Unknown platform: ${platformKey}` };
+  if (!platform.verify) return { ok: null, reason: 'verify-not-configured' };
+
+  const { url, method, okStatuses } = platform.verify;
+  let resp;
+  try {
+    resp = await fetch(url, { method, credentials: 'include', cache: 'no-store' });
+  } catch (e) {
+    return { ok: false, reason: `Verify request failed: ${e.message}` };
+  }
+  if (okStatuses.includes(resp.status)) {
+    return { ok: true, status: resp.status };
+  }
+  return {
+    ok: false,
+    status: resp.status,
+    reason: `${url} returned HTTP ${resp.status} — session looks stale or logged out`,
+  };
+}

extension/lib/platforms.js

@@ -13,6 +13,13 @@ const PLATFORMS = {
     authType: 'cookies',
     color: '#FF424D',
     urlPattern: /^https?:\/\/(www\.)?patreon\.com/,
+    // Patreon's `/api/current_user` returns 200 + the logged-in user
+    // when authenticated, 401 otherwise. Cheapest definitive check.
+    verify: {
+      url: 'https://www.patreon.com/api/current_user',
+      method: 'GET',
+      okStatuses: [200],
+    },
   },
   subscribestar: {
     name: 'SubscribeStar',
@@ -26,6 +33,9 @@ const PLATFORMS = {
     authType: 'cookies',
     color: '#FFD700',
     urlPattern: /^https?:\/\/(www\.)?subscribestar\.(com|adult)/,
+    // No known stable auth-required endpoint that returns a definitive
+    // status code; skipping verify so we don't false-positive-fail
+    // good cookies. Operator can add later if a clean endpoint surfaces.
   },
   hentaifoundry: {
     name: 'Hentai Foundry',
@@ -33,6 +43,14 @@ const PLATFORMS = {
     authType: 'cookies',
     color: '#9C27B0',
     urlPattern: /^https?:\/\/(www\.)?hentai-foundry\.com/,
+    // Mirror gallery-dl's _init_site_filters: HEAD on `?enterAgree=1`.
+    // Logged in → 200, logged out → 401. Catches the exact failure mode
+    // the backend extractor would hit later.
+    verify: {
+      url: 'https://www.hentai-foundry.com/?enterAgree=1',
+      method: 'HEAD',
+      okStatuses: [200],
+    },
   },
   discord: {
     name: 'Discord',
@@ -56,6 +74,9 @@ const PLATFORMS = {
     authType: 'cookies',
     color: '#05CC47',
     urlPattern: /^https?:\/\/(www\.)?deviantart\.com/,
+    // DA's logged-in-only endpoints sit behind their internal _napi
+    // namespace which shifts; skipping verify until a stable check
+    // surfaces. Same posture as SubscribeStar.
   },
 };
 

extension/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "FabledCurator",
-  "version": "1.0.5",
+  "version": "1.0.7",
   "description": "Export cookies from supported platforms to FabledCurator and add creators as sources in one click.",
 
   "browser_specific_settings": {

extension/package.json

@@ -1,6 +1,6 @@
 {
   "name": "fabledcurator-extension",
-  "version": "1.0.5",
+  "version": "1.0.7",
   "private": true,
   "description": "Firefox extension for FabledCurator",
   "scripts": {

extension/popup/popup.js

@@ -132,8 +132,9 @@ async function exportPlatformCookies(key, card) {
     if (r.error) showError(r.error);
     else {
       const n = r.cookieCount ?? null;
+      const verifiedSuffix = r.verified ? ' (verified ✓)' : '';
       const msg = n !== null
-        ? `${PLATFORMS[key].name}: ${n} cookies exported`
+        ? `${PLATFORMS[key].name}: ${n} cookies exported${verifiedSuffix}`
         : `${PLATFORMS[key].name}: token exported`;
       showSuccess(msg);
       await loadPlatformStatus();

frontend/src/App.vue

@@ -9,7 +9,9 @@
 </template>
 
 <script setup>
-import { onMounted, ref } from 'vue'
+import { onMounted, ref, watch } from 'vue'
+import { useRoute } from 'vue-router'
+
 import AppShell from './components/AppShell.vue'
 import AppSnackbar from './components/AppSnackbar.vue'
 import ImageViewer from './components/modal/ImageViewer.vue'
@@ -17,9 +19,20 @@ import { useModalStore } from './stores/modal.js'
 
 const modal = useModalStore()
 const snackbar = ref(null)
+const route = useRoute()
 
 onMounted(() => {
   // Expose snackbar via a simple global so stores can call it without props.
   window.__fcToast = (opts) => snackbar.value?.open(opts)
 })
+
+// Audit 2026-06-02: the modal is an overlay, not a page. When the
+// route changes (RouterLink inside the modal, history back/forward,
+// programmatic push from any view), close the modal so it doesn't
+// hover over a different route. Watching route.name (not the path)
+// keeps within-route nav like /artist/foo → /artist/bar from
+// dismissing the modal mid-browse.
+watch(() => route.name, () => {
+  if (modal.isOpen) modal.close()
+})
 </script>

frontend/src/components/artist/ArtistGalleryTab.vue

@@ -11,9 +11,6 @@
 </template>
 
 <script setup>
-import { onMounted, watch } from 'vue'
-import { useRoute, useRouter } from 'vue-router'
-
 import { useArtistStore } from '../../stores/artist.js'
 import { useModalStore } from '../../stores/modal.js'
 import MasonryGrid from '../discovery/MasonryGrid.vue'
@@ -24,22 +21,9 @@ const props = defineProps({
 
 const store = useArtistStore()
 const modal = useModalStore()
-const route = useRoute()
-const router = useRouter()
-
-onMounted(() => {
-  const initial = parseInt(route.query.image, 10)
-  if (!isNaN(initial)) modal.open(initial)
-})
-
-watch(() => route.query.image, (q) => {
-  const id = parseInt(q, 10)
-  if (!isNaN(id) && id !== modal.currentImageId) modal.open(id)
-  else if (isNaN(id) && modal.currentImageId !== null) modal.close()
-})
 
 function openImage (id) {
-  router.push({ query: { ...route.query, image: id } })
+  modal.open(id)
 }
 </script>
 

frontend/src/components/downloads/DownloadEventRow.vue

@@ -124,10 +124,16 @@ async function onRetry() {
   if (!props.event.source_id) return
   retrying.value = true
   try {
-    await sourcesStore.checkNow(props.event.source_id)
-    toast({
-      text: `Source check re-queued`, type: 'success',
-    })
+    const body = await sourcesStore.checkNow(props.event.source_id)
+    // Audit 2026-06-02: the previous handler unconditionally toasted
+    // "re-queued" even when the platform was in cooldown (202 +
+    // status='deferred'). Operator thought work was in flight when
+    // nothing was actually enqueued.
+    if (body?.status === 'deferred') {
+      toast({ text: 'Retry deferred — platform in cooldown', type: 'info' })
+    } else {
+      toast({ text: 'Source check re-queued', type: 'success' })
+    }
   } catch (e) {
     const isInFlight = !!e?.body?.download_event_id
     toast({

frontend/src/components/modal/AliasPickerDialog.vue

@@ -48,10 +48,11 @@ function onSearch(q) {
     if (!query) { results.value = []; return }
     loading.value = true
     try {
-      // Scope the autocomplete to the prediction's category where it maps
-      // to a tag kind. 'copyright' has no tag kind; search unscoped there.
-      const kind = ['artist', 'character'].includes(props.category)
-        ? props.category : null
+      // Scope the autocomplete to the prediction's category where it
+      // maps to a tag kind. Only 'character' surfaces as both a
+      // suggestion category and a tag kind now ('artist' + 'copyright'
+      // retired); other categories search unscoped.
+      const kind = props.category === 'character' ? 'character' : null
       const params = { q: query, limit: 20 }
       if (kind) params.kind = kind
       results.value = await api.get('/api/tags/autocomplete', { params })

frontend/src/components/modal/ImageViewer.vue

@@ -92,7 +92,16 @@ let prevBodyOverflow = null
 // own keystrokes.
 function onKeyDown(ev) {
   if (ev.key === 'Escape') {
-    if (isTextEntry(ev.target)) return
+    // Escape closes the modal even from inside a text input — that's
+    // the universal "get me out of here" expectation, and the
+    // autofocused tag-entry field would otherwise trap focus with no
+    // visible escape (operator-flagged 2026-06-01). EXCEPTION: when a
+    // nested Vuetify overlay is open (v-menu autocomplete dropdown,
+    // FandomPicker v-dialog, per-suggestion 3-dot menu), let that
+    // overlay's own Esc handling fire instead of closing the whole
+    // modal mid-interaction. Vuetify marks open overlays with
+    // `.v-overlay--active`.
+    if (document.querySelector('.v-overlay--active')) return
     ev.preventDefault()
     emit('close')
   } else if (ev.key === 'ArrowLeft') {

frontend/src/components/modal/ProvenancePanel.vue

@@ -10,17 +10,30 @@
       density="compact"
     >{{ state.error }}</v-alert>
 
-    <template v-else>
+    <!-- Cards scroll independently of the section title + attachments
+         below them. Cap at ~2.5 cards visible (operator-asked 2026-06-01:
+         keeps the Tags section anchored below at a consistent position;
+         the half-visible third card hints there's more). -->
+    <div v-else class="fc-prov__cards">
       <article
         v-for="e in state.entries" :key="e.provenance_id" class="fc-prov__card"
       >
         <div class="fc-prov__head">
-          <span class="fc-prov__platform">{{ e.source.platform }}</span>
+          <!-- Posts with no live subscription have source=null (alembic
+               0030); render an explicit "filesystem import" affordance
+               instead of a platform chip. -->
+          <span class="fc-prov__platform">
+            {{ e.source?.platform ?? 'filesystem import' }}
+          </span>
           <span v-if="postDate(e)" class="fc-prov__date">{{ postDate(e) }}</span>
         </div>
-        <div class="fc-prov__post">
+        <button
+          type="button" class="fc-prov__post"
+          :title="`Open ${postTitle(e)} in the posts feed for ${e.artist.name}`"
+          @click="openPost(e.post.id, e.artist.id)"
+        >
           {{ postTitle(e) }}
-        </div>
+        </button>
         <div class="fc-prov__meta">
           <RouterLink :to="`/artist/${e.artist.slug}`">
             by {{ e.artist.name }}
@@ -29,12 +42,8 @@
             · {{ e.post.attachment_count }} files
           </span>
         </div>
-        <div class="fc-prov__actions">
-          <a href="#" @click.prevent="openPost(e.post.id)">
-            View post
-          </a>
+        <div v-if="e.post.description_html" class="fc-prov__actions">
           <a
-            v-if="e.post.description_html"
             href="#" @click.prevent="toggleDesc(e.provenance_id)"
           >{{ expanded[e.provenance_id] ? 'Hide description ▴' : 'Show description ▾' }}</a>
         </div>
@@ -58,7 +67,7 @@
           </RouterLink>
         </div>
       </article>
-    </template>
+    </div>
 
     <div v-if="attachments.length" class="fc-prov__attach">
       <h4 class="fc-prov__attach-title">Attachments</h4>
@@ -137,10 +146,16 @@ function postTitle(e) {
   return toPlainText(e.post.title) || `Post ${e.post.external_post_id}`
 }
 
-function openPost(postId) {
+function openPost(postId, artistId) {
   // Land on the post in the posts feed (in context), not the gallery
-  // image grid. Operator-flagged 2026-05-28.
-  router.push({ path: '/posts', query: { post_id: postId } })
+  // image grid. Scope the feed to this artist so the user lands in
+  // that creator's stream, not the global one — operator-flagged
+  // 2026-06-01. PostsView reads `artist_id` from the query string
+  // (PostsView.vue line ~92) and filters via post_feed_service.
+  router.push({
+    path: '/posts',
+    query: { post_id: postId, artist_id: artistId },
+  })
   modal.close()
 }
 </script>
@@ -153,6 +168,18 @@ function openPost(postId) {
   color: rgb(var(--v-theme-on-surface));
   margin-bottom: 12px;
 }
+.fc-prov__cards {
+  /* 2.5 cards-worth at the typical collapsed card height (~108px each
+     incl. 10px gap). Slightly under to ensure the third card's bottom
+     edge is clipped — the visual cue that there's more below. */
+  max-height: 270px;
+  overflow-y: auto;
+  /* Hairline scrollbar that doesn't compete with content. */
+  scrollbar-width: thin;
+  scrollbar-color: rgb(var(--v-theme-surface-light)) transparent;
+  /* Pad-right so the scrollbar gutter doesn't squeeze card borders. */
+  padding-right: 4px;
+}
 .fc-prov__card {
   border: 1px solid rgb(var(--v-theme-surface-light));
   border-radius: 6px; padding: 10px 12px; margin-bottom: 10px;
@@ -163,8 +190,21 @@ function openPost(postId) {
   text-transform: lowercase;
 }
 .fc-prov__post {
-  font-weight: 700; margin: 4px 0;
-  color: rgb(var(--v-theme-on-surface));
+  /* Clickable title — opens the post in the artist-scoped feed
+     (operator-flagged 2026-06-01: title IS the primary action, the
+     prior "View post" link was redundant). Styled as a button-link:
+     accent color, underline on hover, focus ring for keyboard nav. */
+  display: block; width: 100%; text-align: left;
+  background: none; border: none; padding: 0;
+  font: inherit; font-weight: 700;
+  margin: 4px 0;
+  color: rgb(var(--v-theme-accent));
+  cursor: pointer;
+}
+.fc-prov__post:hover { text-decoration: underline; }
+.fc-prov__post:focus-visible {
+  outline: 2px solid rgb(var(--v-theme-accent));
+  outline-offset: 2px; border-radius: 3px;
 }
 .fc-prov__meta {
   font-size: 13px; color: rgb(var(--v-theme-on-surface-variant));

frontend/src/components/modal/SuggestionItem.vue

@@ -1,29 +1,52 @@
 <template>
+  <!-- Chip-card row: visible border + hover/focus state unifies the
+       name, score, and action buttons as one "object" (operator-asked
+       2026-06-01). The row itself is informational; the explicit
+       Accept button + 3-dot menu are the action affordances. -->
   <div class="fc-suggestion">
     <span class="fc-suggestion__name">
       {{ suggestion.display_name }}
       <span v-if="suggestion.creates_new_tag" class="fc-suggestion__new"
-        title="No matching tag yet — accepting creates it">＋new</span>
+        title="No matching tag yet — accepting creates it">+ new</span>
     </span>
     <span class="fc-suggestion__score">{{ scorePct }}</span>
     <v-btn
-      icon="mdi-plus" size="x-small" variant="text" color="accent"
+      class="fc-suggestion__accept"
+      size="small" variant="tonal" color="accent"
+      density="compact" rounded="pill"
       :aria-label="`Accept ${suggestion.display_name}`"
       @click="$emit('accept', suggestion)"
-    />
-    <v-menu>
-      <template #activator="{ props }">
-        <v-btn icon="mdi-dots-vertical" size="x-small" variant="text" v-bind="props" />
-      </template>
-      <v-list density="compact">
-        <v-list-item @click="$emit('alias', suggestion)">
-          <v-list-item-title>Treat as alias for…</v-list-item-title>
-        </v-list-item>
-        <v-list-item @click="$emit('dismiss', suggestion)">
-          <v-list-item-title>Dismiss for this image</v-list-item-title>
-        </v-list-item>
-      </v-list>
-    </v-menu>
+    >
+      Accept
+    </v-btn>
+    <!-- Operator-flagged 2026-06-02: the kebab menu wasn't opening.
+         Wrapping in a <span @click.stop> matches the TagPanel chip
+         fix — even though there's no parent click capture here today,
+         the wrap is harmless and keeps both kebabs on the same
+         pattern. Click bubbles from the v-btn → opens menu via
+         activator props → bubble continues to span → stopPropagation
+         halts it. -->
+    <span class="fc-suggestion__menu-wrap" @click.stop>
+      <v-menu>
+        <template #activator="{ props }">
+          <v-btn
+            class="fc-suggestion__menu"
+            icon="mdi-dots-vertical" size="small"
+            variant="outlined" density="compact"
+            :aria-label="`More actions for ${suggestion.display_name}`"
+            v-bind="props"
+          />
+        </template>
+        <v-list density="compact">
+          <v-list-item @click="$emit('alias', suggestion)">
+            <v-list-item-title>Treat as alias for…</v-list-item-title>
+          </v-list-item>
+          <v-list-item @click="$emit('dismiss', suggestion)">
+            <v-list-item-title>Dismiss for this image</v-list-item-title>
+          </v-list-item>
+        </v-list>
+      </v-menu>
+    </span>
   </div>
 </template>
 
@@ -38,17 +61,50 @@ const scorePct = computed(() => `${Math.round(props.suggestion.score * 100)}%`)
 
 <style scoped>
 .fc-suggestion {
-  display: flex; align-items: center; gap: 6px;
-  padding: 2px 0;
+  display: flex; align-items: center; gap: 8px;
+  padding: 6px 10px; margin-bottom: 4px;
+  background: rgb(var(--v-theme-surface));
+  border: 1px solid rgb(var(--v-theme-surface-light));
+  border-radius: 6px;
+  transition: background 120ms ease, border-color 120ms ease;
+}
+.fc-suggestion:hover {
+  background: rgb(var(--v-theme-surface-light));
+  border-color: rgb(var(--v-theme-accent), 0.4);
+}
+.fc-suggestion__name {
+  flex: 1; min-width: 0;
+  font-size: 14px;
+  color: rgb(var(--v-theme-on-surface));
+  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
 }
-.fc-suggestion__name { flex: 1; min-width: 0; }
 .fc-suggestion__new {
-  font-size: 10px; color: rgb(var(--v-theme-accent));
-  margin-left: 4px;
+  display: inline-block;
+  font-size: 10px; font-weight: 600;
+  color: rgb(var(--v-theme-accent));
+  background: rgba(var(--v-theme-accent), 0.12);
+  border: 1px solid rgb(var(--v-theme-accent), 0.4);
+  padding: 1px 6px; border-radius: 999px;
+  margin-left: 6px;
+  text-transform: uppercase; letter-spacing: 0.04em;
 }
 .fc-suggestion__score {
+  flex: 0 0 auto; min-width: 38px; text-align: right;
   font-size: 11px;
   color: rgb(var(--v-theme-on-surface-variant, var(--v-theme-on-surface)));
   font-family: 'JetBrains Mono', monospace;
 }
+/* Vuetify's compact density doesn't shrink the tonal button enough
+   for a tight row; clamp the min-width so Accept stays compact. */
+.fc-suggestion__accept :deep(.v-btn__content) {
+  font-size: 12px; letter-spacing: 0.02em;
+}
+.fc-suggestion__menu-wrap {
+  flex: 0 0 auto;
+  display: inline-flex;
+  align-items: center;
+}
+.fc-suggestion__menu {
+  flex: 0 0 auto;
+}
 </style>

frontend/src/components/modal/SuggestionsPanel.vue

@@ -22,7 +22,7 @@
       <SuggestionsCategoryGroup
         v-if="store.byCategory.general && store.byCategory.general.length"
         label="General" :items="store.byCategory.general"
-        collapsible :default-open="false"
+        collapsible :default-open="true"
         @accept="onAccept" @alias="onAlias" @dismiss="store.dismiss"
       />
     </template>
@@ -41,13 +41,18 @@
 import { toast } from '../../utils/toast.js'
 import { computed, ref, watch } from 'vue'
 import { useSuggestionsStore, CATEGORY_LABELS } from '../../stores/suggestions.js'
+import { useModalStore } from '../../stores/modal.js'
 import SuggestionsCategoryGroup from './SuggestionsCategoryGroup.vue'
 import AliasPickerDialog from './AliasPickerDialog.vue'
 
 const props = defineProps({ imageId: { type: Number, required: true } })
 const store = useSuggestionsStore()
+const modal = useModalStore()
 
-const peopleCats = ['artist', 'character', 'copyright']
+// 'artist' (FC-2d-vii-c) and 'copyright' (2026-06-01) retired as
+// suggestion categories. Only 'character' remains as a people-style
+// category alongside the general bucket.
+const peopleCats = ['character']
 function labelFor(c) { return CATEGORY_LABELS[c] || c }
 
 const isEmpty = computed(() =>
@@ -56,9 +61,20 @@ const isEmpty = computed(() =>
 
 watch(() => props.imageId, (id) => { if (id != null) store.load(id) }, { immediate: true })
 
+// After a successful accept/alias-accept, refresh the modal's current
+// tag list so TagPanel's chip rail reflects the newly-attached tag.
+// Operator-flagged 2026-06-01: the suggestion store dropped the
+// suggestion (correct) but didn't propagate the new tag back into the
+// modal store, so the chip rail looked unchanged even though the
+// backend had recorded the application. Mirrors the addExistingTag /
+// createAndAdd flows which already call reloadTags() after applying.
 async function onAccept(s) {
-  try { await store.accept(s) }
-  catch (e) { toast({ text: `Accept failed: ${e.message}`, type: 'error' }) }
+  try {
+    await store.accept(s)
+    await modal.reloadTags()
+  } catch (e) {
+    toast({ text: `Accept failed: ${e.message}`, type: 'error' })
+  }
 }
 
 const aliasDialog = ref(false)
@@ -68,6 +84,7 @@ async function onAliasConfirm(canonicalTagId) {
   try {
     await store.aliasAccept(aliasTarget.value, canonicalTagId)
     aliasDialog.value = false
+    await modal.reloadTags()
   } catch (e) {
     toast({ text: `Alias failed: ${e.message}`, type: 'error' })
   }

frontend/src/components/modal/TagAutocomplete.vue

@@ -1,6 +1,7 @@
 <template>
   <div class="fc-tag-autocomplete">
     <v-text-field
+      ref="inputRef"
       v-model="query"
       placeholder="Add tag (or kind:name — character/fandom/series)"
       density="compact" hide-details
@@ -52,13 +53,21 @@
 </template>
 
 <script setup>
-import { computed, ref, watch } from 'vue'
+import { computed, nextTick, onMounted, ref, watch } from 'vue'
 import { useTagStore } from '../../stores/tags.js'
 import FandomPicker from './FandomPicker.vue'
 
 const emit = defineEmits(['pick-existing', 'pick-new', 'cancel'])
 const store = useTagStore()
 
+// Autofocus on modal open so the operator can type the moment the view
+// modal renders, no extra click required (operator-asked 2026-06-01).
+// Vuetify's v-text-field exposes .focus() on the component instance;
+// nextTick waits for the modal's mount to finish so the inner <input>
+// element exists.
+const inputRef = ref(null)
+onMounted(() => { nextTick(() => inputRef.value?.focus?.()) })
+
 // Single text input; no kind dropdown. Client-side mirror of the
 // backend's parse_kind_prefix lives below — kept in sync with
 // KNOWN_KINDS in backend/app/utils/tag_prefix.py. The backend is the

frontend/src/components/modal/TagPanel.vue

@@ -10,19 +10,27 @@
       >
         <v-icon start size="x-small">{{ iconFor(tag.kind) }}</v-icon>
         {{ tag.name }}<span v-if="tag.fandom_id">→</span>
-        <v-menu>
-          <template #activator="{ props: mp }">
-            <v-icon
-              v-bind="mp" size="x-small" class="ml-1"
-              icon="mdi-dots-vertical" @click.stop
-            />
-          </template>
-          <v-list density="compact">
-            <v-list-item @click="openRename(tag)">
-              <v-list-item-title>Rename…</v-list-item-title>
-            </v-list-item>
-          </v-list>
-        </v-menu>
+        <!-- Operator-flagged 2026-06-02: the previous activator had
+             `@click.stop` directly on the v-icon, which silently
+             overrode Vuetify's onClick from `v-bind="mp"` — the menu
+             never opened. Now the v-icon receives the activator
+             onClick cleanly, and the wrapping span absorbs the
+             bubbled click so the chip's close button isn't tripped. -->
+        <span class="kebab-wrap" @click.stop>
+          <v-menu>
+            <template #activator="{ props: mp }">
+              <v-icon
+                v-bind="mp" size="x-small" class="ml-1"
+                icon="mdi-dots-vertical"
+              />
+            </template>
+            <v-list density="compact">
+              <v-list-item @click="openRename(tag)">
+                <v-list-item-title>Rename…</v-list-item-title>
+              </v-list-item>
+            </v-list>
+          </v-menu>
+        </span>
       </v-chip>
       <span v-if="!modal.current?.tags?.length" class="text-caption">No tags yet.</span>
     </div>
@@ -113,4 +121,5 @@ async function onRenamed() {
   margin-bottom: 12px;
 }
 .fc-tag-panel__chips { display: flex; flex-wrap: wrap; gap: 6px; }
+.kebab-wrap { display: inline-flex; align-items: center; }
 </style>

frontend/src/components/posts/PostCard.vue

@@ -7,7 +7,12 @@
     @keydown.enter="onCardClick"
   >
     <div class="fc-post-card__head">
-      <v-chip size="x-small" variant="tonal">{{ post.source.platform }}</v-chip>
+      <!-- Posts with no live subscription have source=null (alembic
+           0030); show a "filesystem import" affordance instead of a
+           platform chip. -->
+      <v-chip size="x-small" variant="tonal">
+        {{ post.source?.platform ?? 'filesystem import' }}
+      </v-chip>
       <RouterLink
         :to="{ name: 'artist', params: { slug: post.artist.slug } }"
         class="fc-post-card__artist"
@@ -25,7 +30,7 @@
         v-if="post.post_url"
         :href="post.post_url" target="_blank" rel="noopener"
         icon="mdi-open-in-new" size="x-small" variant="text"
-        :aria-label="`open original post on ${post.source.platform}`"
+        :aria-label="`open original post on ${post.source?.platform ?? 'web'}`"
         @click.stop
       />
       <v-btn

frontend/src/components/settings/MLThresholdSliders.vue

@@ -22,10 +22,10 @@ import { reactive, watch } from 'vue'
 import { useMLStore } from '../../stores/ml.js'
 
 const store = useMLStore()
+// 'artist' (FC-2d-vii-c) and 'copyright' (2026-06-01) retired as
+// suggestion categories; their threshold rows are gone.
 const fields = [
-  { key: 'suggestion_threshold_artist', label: 'Artist' },
   { key: 'suggestion_threshold_character', label: 'Character' },
-  { key: 'suggestion_threshold_copyright', label: 'Copyright' },
   { key: 'suggestion_threshold_general', label: 'General' },
   { key: 'centroid_similarity_threshold', label: 'Centroid similarity' }
 ]

frontend/src/components/settings/QueuesTable.vue

@@ -35,7 +35,7 @@ import { computed } from 'vue'
 const props = defineProps({
   queues: { type: Object, default: null },     // store.queues
   workers: { type: Object, default: null },    // store.workers
-  recentMinute: { type: Array, default: () => [] }, // store.recentMinute
+  recentRuns: { type: Array, default: () => [] }, // store.recentRuns
   compact: { type: Boolean, default: false },
 })
 
@@ -80,7 +80,7 @@ function activeCount(name) {
 
 const recentByQueue = computed(() => {
   const out = {}
-  for (const r of props.recentMinute) {
+  for (const r of props.recentRuns) {
     if (!out[r.queue]) out[r.queue] = { ok: 0, err: 0 }
     if (r.status === 'ok') out[r.queue].ok++
     else if (r.status === 'error' || r.status === 'timeout') out[r.queue].err++

frontend/src/components/settings/SystemActivitySummary.vue

@@ -24,7 +24,7 @@
       <QueuesTable
         :queues="store.queues"
         :workers="store.workers"
-        :recent-minute="store.recentMinute"
+        :recent-runs="store.recentRuns"
         compact
       />
     </v-card-text>
@@ -47,7 +47,7 @@ function pollOnce() {
   if (document.hidden) return
   store.loadQueues()
   store.loadWorkers()
-  store.loadRecentMinute()
+  store.loadRecentRuns()
 }
 
 onMounted(() => {

frontend/src/components/settings/SystemActivityTab.vue

@@ -14,7 +14,7 @@
         <QueuesTable
           :queues="store.queues"
           :workers="store.workers"
-          :recent-minute="store.recentMinute"
+          :recent-runs="store.recentRuns"
         />
       </v-card-text>
     </v-card>
@@ -202,7 +202,7 @@ function pollQueues() {
   if (document.hidden) return
   store.loadQueues()
   store.loadWorkers()
-  store.loadRecentMinute()
+  store.loadRecentRuns()
 }
 function pollFailures() {
   if (document.hidden) return

frontend/src/components/settings/ThumbnailBackfillCard.vue

@@ -10,7 +10,14 @@
       <v-btn color="primary" rounded="pill" :loading="busy" @click="run">
         <v-icon start>mdi-image-refresh</v-icon> Run backfill now
       </v-btn>
-      <span v-if="done" class="ml-3 text-caption">Enqueued.</span>
+      <span v-if="result" class="ml-3 text-caption">
+        Scanned <strong>{{ result.scanned }}</strong> · enqueued
+        <strong>{{ result.enqueued }}</strong>
+        <span v-if="result.regenerated > 0">
+          ({{ result.regenerated }} regenerated)
+        </span>
+        · {{ result.ok }} ok
+      </span>
       <QueueStatusBar queue="thumbnail" queue-label="Thumbnail" />
     </v-card-text>
   </v-card>
@@ -23,10 +30,11 @@ import { useThumbnailsStore } from '../../stores/thumbnails.js'
 import QueueStatusBar from './QueueStatusBar.vue'
 const store = useThumbnailsStore()
 const busy = ref(false)
-const done = ref(false)
+const result = ref(null)
 async function run () {
   busy.value = true
-  try { await store.triggerBackfill(); done.value = true }
+  result.value = null
+  try { result.value = await store.triggerBackfill() }
   catch (e) { toast({ text: e.message, type: 'error' }) }
   finally { busy.value = false }
 }

frontend/src/components/subscriptions/DownloadsTab.vue

@@ -58,6 +58,7 @@
       :retrying-all="retryingAll"
       @retry="onRetrySource"
       @retry-all="onRetryAll"
+      @view-logs="onViewFailingLogs"
     />
 
     <div v-if="store.loading && store.events.length === 0" class="fc-dl__loading">
@@ -364,6 +365,23 @@ watch(filterModel, async (m) => {
 async function openDetail(id) {
   await store.loadOne(id)
 }
+
+async function onViewFailingLogs(source) {
+  // Find and open the most recent DownloadEvent for this source.
+  // Reuses the existing DownloadDetailModal — same stdout/stderr/error
+  // surface the row-click in the events feed shows.
+  try {
+    const ev = await store.loadLastForSource(source.id)
+    if (!ev) {
+      toast({
+        text: `No download events recorded for ${source.artist_name || source.platform} yet.`,
+        type: 'warning',
+      })
+    }
+  } catch (e) {
+    toast({ text: `Failed to load logs: ${e.message}`, type: 'error' })
+  }
+}
 </script>
 
 <style scoped>

frontend/src/components/subscriptions/FailingSourcesCard.vue

@@ -25,10 +25,27 @@
           <v-chip size="x-small" color="error" variant="flat" label class="fc-fail__count">
             {{ s.consecutive_failures }}× failed
           </v-chip>
+          <v-chip
+            v-if="s.error_type"
+            size="x-small" variant="outlined" label
+            :color="errorTypeColor(s.error_type)"
+            class="fc-fail__class"
+            :title="errorTypeHint(s.error_type)"
+          >
+            {{ s.error_type }}
+          </v-chip>
           <span class="fc-fail__err" :title="s.last_error || ''">
             {{ s.last_error || 'no error message recorded' }}
           </span>
           <v-spacer />
+          <v-btn
+            size="x-small" variant="text" prepend-icon="mdi-text-box-search-outline"
+            :loading="logLoadingIds.has(s.id)"
+            @click="onViewLogs(s)"
+            title="Show the most recent download event's stdout/stderr/error"
+          >
+            Logs
+          </v-btn>
           <v-btn
             size="x-small" variant="text" prepend-icon="mdi-refresh"
             :loading="retryingIds.has(s.id)"
@@ -52,9 +69,59 @@ defineProps({
   retryingIds: { type: Set, default: () => new Set() },
   retryingAll: { type: Boolean, default: false },
 })
-defineEmits(['retry', 'retry-all'])
+const emit = defineEmits(['retry', 'retry-all', 'view-logs'])
 
 const open = ref(true)
+// Per-row loading flag so the spinner lives on the row whose Logs
+// button was clicked, not on every row.
+const logLoadingIds = ref(new Set())
+
+// Audit 2026-06-02: surface the ErrorType taxonomy as a colored chip
+// next to the consecutive-failures count so operators can bulk-triage
+// by error class. Color reflects "what to do next":
+//   warning (yellow) — auth/cookie issue: operator should rotate
+//   info (blue)      — backend-paced (cooldown / rate limit / timeout)
+//   error (red)      — likely terminal without operator intervention
+const ERROR_TYPE_COLOR = {
+  auth_error: 'warning',
+  rate_limited: 'info',
+  timeout: 'info',
+  network_error: 'info',
+  not_found: 'error',
+  access_denied: 'error',
+  validation_failed: 'error',
+  unsupported_url: 'error',
+  http_error: 'error',
+  unknown_error: 'error',
+  partial: 'info',
+  tier_limited: 'info',
+  no_new_content: 'info',
+}
+const ERROR_TYPE_HINT = {
+  auth_error: 'Cookies likely expired — re-upload in Credentials.',
+  rate_limited: 'Platform-wide cooldown active. Will retry after it expires.',
+  timeout: 'Subprocess exceeded its time budget. Often retries cleanly.',
+  network_error: 'Transient network issue. Will retry on next tick.',
+  not_found: 'URL 404 — creator may have renamed or deleted.',
+  access_denied: 'Subscription tier may not grant this content.',
+  validation_failed: 'Downloaded files were quarantined by the validator.',
+  http_error: 'Generic HTTP error — see Logs.',
+  unsupported_url: 'gallery-dl does not support this URL pattern.',
+  unknown_error: 'Could not classify — see Logs.',
+}
+function errorTypeColor(t) { return ERROR_TYPE_COLOR[t] || 'error' }
+function errorTypeHint(t) { return ERROR_TYPE_HINT[t] || '' }
+async function onViewLogs(s) {
+  if (logLoadingIds.value.has(s.id)) return
+  logLoadingIds.value = new Set(logLoadingIds.value).add(s.id)
+  try {
+    await emit('view-logs', s)
+  } finally {
+    const next = new Set(logLoadingIds.value)
+    next.delete(s.id)
+    logLoadingIds.value = next
+  }
+}
 </script>
 
 <style scoped>
@@ -68,16 +135,32 @@ const open = ref(true)
 .fc-fail__title { font-weight: 600; }
 .fc-fail__body {
   padding: 0 14px 10px;
-  display: flex; flex-direction: column; gap: 2px;
+  display: flex; flex-direction: column;
+  /* Borders, not gap, so the row separators are visible inside the
+   * tonal error card (where surface tints get washed out and gap is
+   * just empty space). */
 }
 .fc-fail__row {
   display: flex; align-items: center; gap: 10px;
-  padding: 6px 8px;
+  padding: 8px 10px;
   border-radius: 4px;
-  background: rgb(var(--v-theme-surface) / 0.4);
+  /* Hover-darken gives the eye a horizontal track from the artist
+   * name on the left to the Logs/Retry buttons on the right.
+   * Bottom border replaces the previous-too-subtle zebra striping —
+   * inside the tonal error card, surface-tint contrast was negligible.
+   * Operator-flagged 2026-06-01 (twice). */
+  border-bottom: 1px solid rgb(255 255 255 / 0.08);
+  transition: background 80ms ease;
+}
+.fc-fail__row:last-child {
+  border-bottom: none;
+}
+.fc-fail__row:hover {
+  background: rgb(0 0 0 / 0.25);
 }
 .fc-fail__artist { font-weight: 600; white-space: nowrap; }
 .fc-fail__count { flex: 0 0 auto; }
+.fc-fail__class { flex: 0 0 auto; }
 .fc-fail__err {
   color: rgb(var(--v-theme-on-surface-variant));
   font-size: 0.8rem;

frontend/src/components/subscriptions/SourceRow.vue

@@ -31,6 +31,12 @@
         v-if="(source.consecutive_failures || 0) > 0"
         size="x-small" color="error" variant="tonal" label
       >{{ source.consecutive_failures }}</v-chip>
+      <v-chip
+        v-else-if="(source.backfill_runs_remaining || 0) > 0"
+        size="x-small" color="info" variant="tonal" label
+      >
+        backfill ({{ source.backfill_runs_remaining }}×)
+      </v-chip>
       <span v-else class="fc-source-row__zero">0</span>
     </td>
     <td class="fc-source-row__actions">
@@ -42,6 +48,16 @@
         <v-icon>mdi-play</v-icon>
         <v-tooltip activator="parent" location="top">Check now</v-tooltip>
       </v-btn>
+      <v-btn
+        icon="mdi-magnify-scan" size="x-small" variant="text"
+        :disabled="(source.backfill_runs_remaining || 0) > 0"
+        @click.stop="$emit('backfill', source)"
+      >
+        <v-icon>mdi-magnify-scan</v-icon>
+        <v-tooltip activator="parent" location="top">
+          Deep scan — walk full history for next few runs
+        </v-tooltip>
+      </v-btn>
       <v-btn
         icon="mdi-pencil" size="x-small" variant="text"
         @click.stop="$emit('edit', source)"
@@ -69,7 +85,7 @@ const props = defineProps({
   checking: { type: Boolean, default: false },
   warningThreshold: { type: Number, default: 5 },
 })
-const emit = defineEmits(['edit', 'remove', 'toggle', 'check'])
+const emit = defineEmits(['edit', 'remove', 'toggle', 'check', 'backfill'])
 
 function onToggleEnabled(value) {
   emit('toggle', { source: props.source, enabled: value })

frontend/src/components/subscriptions/SubscriptionsTab.vue

@@ -174,6 +174,7 @@
                     @remove="removeSource"
                     @toggle="toggleSourceEnabled"
                     @check="onCheck"
+                    @backfill="onBackfill"
                   />
                   <tr v-if="item.sources.length === 0">
                     <td colspan="8" class="fc-subs__sources-empty">
@@ -411,6 +412,17 @@ function onArtistCreated(artist) {
 async function onCheck(source) {
   try {
     const body = await store.checkNow(source.id)
+    // Audit 2026-06-02: /api/sources/<id>/check returns 202 with
+    // `{status:'deferred', cooldown_until}` when the platform is in
+    // cooldown — the previous handler treated this as success and
+    // toasted "event #undefined", masking that nothing was enqueued.
+    if (body?.status === 'deferred') {
+      toast({
+        text: 'Check deferred — platform in cooldown',
+        type: 'info',
+      })
+      return
+    }
     toast({
       text: `Check enqueued (event #${body.download_event_id})`,
       type: 'success',
@@ -431,20 +443,56 @@ async function onCheck(source) {
   }
 }
 
+// Plan #544: arm a source for backfill mode (gallery-dl walks the full
+// post history) for the next N download runs. Default 3 — enough budget
+// to finish a deep creator without re-prompting the operator across
+// timeout boundaries. The chip on the row reflects the remaining count.
+async function onBackfill(source) {
+  const raw = globalThis.window?.prompt(
+    `Deep scan "${source.artist_name} (${source.platform})" — walk full history for the next how many download runs? (1–10, default 3)`,
+    '3',
+  )
+  if (raw == null) return
+  const runs = parseInt(raw, 10)
+  if (!Number.isFinite(runs) || runs < 1 || runs > 10) {
+    toast({ text: 'Deep scan: runs must be 1–10', type: 'error' })
+    return
+  }
+  try {
+    await store.setBackfill(source.id, runs, source.artist_id)
+    toast({
+      text: `Deep scan armed for ${runs} run${runs === 1 ? '' : 's'}`,
+      type: 'success',
+    })
+    await store.loadAll()
+  } catch (e) {
+    toast({
+      text: `Deep scan failed: ${e?.detail || e?.message || e}`,
+      type: 'error',
+    })
+  }
+}
+
 async function checkAll(group) {
   let ok = 0
   let conflict = 0
+  let deferred = 0
   for (const s of group.sources) {
     if (!s.enabled) continue
     try {
-      await store.checkNow(s.id)
-      ok += 1
+      const body = await store.checkNow(s.id)
+      // Audit 2026-06-02: deferred (202 + cooldown_until) used to be
+      // counted as queued, inflating the success tally and hiding
+      // that the cooldown actually held the work back.
+      if (body?.status === 'deferred') deferred += 1
+      else ok += 1
     } catch (e) {
       if (e?.body?.download_event_id) conflict += 1
     }
   }
   const parts = []
   if (ok) parts.push(`${ok} queued`)
+  if (deferred) parts.push(`${deferred} deferred (cooldown)`)
   if (conflict) parts.push(`${conflict} already running`)
   toast({
     text: parts.join(', ') || 'Nothing to check (no enabled sources)',

frontend/src/composables/useInflightToken.js

@@ -0,0 +1,52 @@
+// Inflight-token guard for stores whose async loads can be re-triggered
+// by rapid filter/navigation changes. Without this, late responses
+// from a prior load overwrite the store with stale data
+// (last-writer-wins, not request-order-wins). gallery.js had a
+// hand-rolled `inflightId` of the same shape; this composable
+// extracts it so every store can use the same pattern.
+//
+// Audit 2026-06-02 (workflow wf_bbe3fdb1-e62) found this missing in
+// modal/suggestions/artist/downloads/directory/posts. The two most
+// operator-impacting consequences: (1) modal tag mutations could
+// land DELETE/POST on the wrong image when the user navigated mid-
+// flight; (2) suggestions accept could push a tag to the wrong
+// image AND add it to the allowlist.
+//
+// Usage:
+//   const inflight = useInflightToken()
+//
+//   async function load() {
+//     const t = inflight.claim()
+//     const body = await api.get(...)
+//     if (!t.isCurrent()) return        // stale — abort write
+//     items.value = body.items          // safe to commit
+//   }
+//
+//   function setFilter(f) {
+//     inflight.cancel()                 // any in-flight token is now stale
+//     filter.value = f
+//     load()                            // claims a fresh token
+//   }
+//
+// For multi-await flows (POST then GET, optimistic mutation then
+// reconcile), check isCurrent() after EACH await — any intervening
+// claim() or cancel() invalidates the prior token.
+export function useInflightToken() {
+  let _seq = 0
+  let _current = 0
+
+  function claim() {
+    _current = ++_seq
+    const id = _current
+    return {
+      id,
+      isCurrent: () => _current === id,
+    }
+  }
+
+  function cancel() {
+    _current = ++_seq
+  }
+
+  return { claim, cancel }
+}

frontend/src/stores/artist.js

@@ -1,6 +1,7 @@
 import { defineStore } from 'pinia'
 import { ref, computed } from 'vue'
 import { useApi } from '../composables/useApi.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 import { usePostsStore } from './posts.js'
 
 const PAGE = 60
@@ -15,12 +16,17 @@ export const useArtistStore = defineStore('artist', () => {
   const error = ref(null)
   const notFound = ref(false)
   let started = false
+  // Rapid artist-to-artist navigation used to render the previous
+  // artist's overview/images briefly when the second load resolved
+  // after the third. Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   async function load (slug) {
     // Cross-artist reset: clear this store AND the posts store so the new
     // artist doesn't briefly render with the previous artist's content
     // when the user is on the Posts tab. (Gallery tab uses this artist
     // store's own images list — cleared above.)
+    inflight.cancel()
     overview.value = null
     images.value = []
     nextCursor.value = null
@@ -29,14 +35,18 @@ export const useArtistStore = defineStore('artist', () => {
     error.value = null
     loading.value = true
     usePostsStore().$reset?.()
+    const t = inflight.claim()
     try {
-      overview.value = await api.get(`/api/artist/${encodeURIComponent(slug)}`)
+      const body = await api.get(`/api/artist/${encodeURIComponent(slug)}`)
+      if (!t.isCurrent()) return
+      overview.value = body
       await loadMoreImages(slug)
     } catch (e) {
+      if (!t.isCurrent()) return
       if (e.status === 404) notFound.value = true
       else error.value = e.message
     } finally {
-      loading.value = false
+      if (t.isCurrent()) loading.value = false
     }
   }
 
@@ -44,19 +54,22 @@ export const useArtistStore = defineStore('artist', () => {
     if (imagesLoading.value) return
     if (started && nextCursor.value === null) return
     imagesLoading.value = true
+    const t = inflight.claim()
     try {
       const params = { limit: PAGE }
       if (nextCursor.value) params.cursor = nextCursor.value
       const body = await api.get(
         `/api/artist/${encodeURIComponent(slug)}/images`, { params }
       )
+      if (!t.isCurrent()) return
       images.value.push(...body.images)
       nextCursor.value = body.next_cursor
       started = true
     } catch (e) {
+      if (!t.isCurrent()) return
       error.value = e.message
     } finally {
-      imagesLoading.value = false
+      if (t.isCurrent()) imagesLoading.value = false
     }
   }
 

frontend/src/stores/artistDirectory.js

@@ -2,6 +2,7 @@ import { defineStore } from 'pinia'
 import { ref, computed } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 const PAGE = 60
 
@@ -13,16 +14,23 @@ export const useArtistDirectoryStore = defineStore('artistDirectory', () => {
   const q = ref('')
   const platform = ref(null)
   let started = false
+  // Typed "alice" then "alice bob" used to drop the second fetch
+  // entirely (loading flag still true from the first), so the UI
+  // showed alice results while the input said "alice bob". Inflight
+  // token + reset() cancelling in-flight requests fixes both: the
+  // first response is discarded, the second is fetched. Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   async function loadMore() {
-    if (loading.value) return
     if (started && nextCursor.value === null) return
+    const t = inflight.claim()
     await run(async () => {
       const params = { limit: PAGE }
       if (q.value) params.q = q.value
       if (platform.value) params.platform = platform.value
       if (nextCursor.value) params.cursor = nextCursor.value
       const body = await api.get('/api/artists/directory', { params })
+      if (!t.isCurrent()) return
       cards.value.push(...body.cards)
       nextCursor.value = body.next_cursor
       started = true
@@ -30,6 +38,7 @@ export const useArtistDirectoryStore = defineStore('artistDirectory', () => {
   }
 
   async function reset() {
+    inflight.cancel()
     cards.value = []
     nextCursor.value = null
     started = false

frontend/src/stores/credentials.js

@@ -23,7 +23,11 @@ export const useCredentialsStore = defineStore('credentials', () => {
     const rec = await api.post('/api/credentials', {
       body: { platform, credential_type, data },
     })
-    byPlatform.value.delete(platform)
+    // Reflect the returned record immediately — the previous .delete()
+    // call left the card rendering "no credential" for the gap between
+    // upload completion and the caller's follow-up loadAll(). Audit
+    // 2026-06-02.
+    byPlatform.value.set(platform, rec)
     return rec
   }
 

frontend/src/stores/downloads.js

@@ -2,6 +2,7 @@ import { defineStore } from 'pinia'
 import { ref } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 export const useDownloadsStore = defineStore('downloads', () => {
   const api = useApi()
@@ -22,6 +23,10 @@ export const useDownloadsStore = defineStore('downloads', () => {
   // the "active now" panel always reflects what's happening regardless of
   // how the operator has filtered the historical list below.
   const activeEvents = ref([])
+  // Filter changes (applyFilter) and rapid pagination can interleave
+  // responses; without an inflight guard the late response from a
+  // prior filter overwrites the current view. Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   function _params(extra = {}) {
     const out = { limit: 50, ...extra }
@@ -32,8 +37,10 @@ export const useDownloadsStore = defineStore('downloads', () => {
   }
 
   async function loadFirst() {
+    const t = inflight.claim()
     await run(async () => {
       const body = await api.get('/api/downloads', { params: _params() })
+      if (!t.isCurrent()) return
       events.value = body
       cursor.value = body.length ? body[body.length - 1].id : null
       hasMore.value = body.length === 50
@@ -42,8 +49,10 @@ export const useDownloadsStore = defineStore('downloads', () => {
 
   async function loadMore() {
     if (!hasMore.value || cursor.value == null) return
+    const t = inflight.claim()
     await run(async () => {
       const body = await api.get('/api/downloads', { params: _params({ before: cursor.value }) })
+      if (!t.isCurrent()) return
       events.value.push(...body)
       cursor.value = body.length ? body[body.length - 1].id : cursor.value
       hasMore.value = body.length === 50
@@ -55,7 +64,25 @@ export const useDownloadsStore = defineStore('downloads', () => {
     return selected.value
   }
 
+  // Open the detail modal for the most recent DownloadEvent of a given
+  // source. Used by the failing-sources rollup's "Logs" button so the
+  // operator can troubleshoot without leaving the Downloads tab to find
+  // the row (operator-flagged 2026-06-01).
+  async function loadLastForSource(sourceId) {
+    const events = await api.get('/api/downloads', {
+      params: { source_id: sourceId, limit: 1 },
+    })
+    if (!events.length) {
+      selected.value = null
+      return null
+    }
+    return await loadOne(events[0].id)
+  }
+
   async function applyFilter(patch) {
+    // Drop any in-flight loadFirst/loadMore from the previous filter
+    // so its late response doesn't overwrite this filter's results.
+    inflight.cancel()
     filter.value = { ...filter.value, ...patch }
     await loadFirst()
   }
@@ -98,7 +125,8 @@ export const useDownloadsStore = defineStore('downloads', () => {
   return {
     events, cursor, hasMore, filter, selected, loading, error, stats,
     activity, failing, activeEvents,
-    loadFirst, loadMore, loadOne, applyFilter, closeDetail, loadStats,
+    loadFirst, loadMore, loadOne, loadLastForSource, applyFilter,
+    closeDetail, loadStats,
     loadActivity, loadFailing, loadActive, recoverStalled,
   }
 })

frontend/src/stores/gallery.js

@@ -1,6 +1,7 @@
 import { defineStore } from 'pinia'
 import { ref, computed } from 'vue'
 import { useApi } from '../composables/useApi.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 // Operator-confirmed 2026-05-30: fetch PAGE-sized chunks instead of one
 // 50-item request so items render as each batch lands. Total initial
@@ -22,9 +23,12 @@ export const useGalleryStore = defineStore('gallery', () => {
   const timelineBuckets = ref([])
   const timelineLoading = ref(false)
 
-  let inflightId = 0
+  // Was a hand-rolled inflightId counter; the audit-2026-06-02 fan-out
+  // moved this pattern into useInflightToken so every store can share it.
+  const inflight = useInflightToken()
 
   async function loadInitial() {
+    inflight.cancel()
     images.value = []
     dateGroups.value = []
     nextCursor.value = null
@@ -41,19 +45,19 @@ export const useGalleryStore = defineStore('gallery', () => {
     if (loading.value) return
     loading.value = true
     error.value = null
-    const myId = ++inflightId
+    const t = inflight.claim()
     try {
       const params = { limit: PAGE, ...activeFilterParam() }
       if (nextCursor.value) params.cursor = nextCursor.value
       const body = await api.get('/api/gallery/scroll', { params })
-      if (myId !== inflightId) return  // stale response
+      if (!t.isCurrent()) return
       images.value.push(...body.images)
       dateGroups.value = mergeGroups(dateGroups.value, body.date_groups)
       nextCursor.value = body.next_cursor
     } catch (e) {
       error.value = e.message
     } finally {
-      if (myId === inflightId) loading.value = false
+      if (t.isCurrent()) loading.value = false
     }
   }
 
@@ -68,8 +72,14 @@ export const useGalleryStore = defineStore('gallery', () => {
   }
 
   async function jumpTo(year, month) {
+    // Rapid timeline-jump clicks need the same race guard as
+    // loadMore — first jump's late body could clobber the second
+    // jump's already-applied state.
+    inflight.cancel()
+    const t = inflight.claim()
     const params = { year, month, ...activeFilterParam() }
     const body = await api.get('/api/gallery/jump', { params })
+    if (!t.isCurrent()) return
     if (body.cursor) {
       images.value = []
       dateGroups.value = []

frontend/src/stores/modal.js

@@ -3,6 +3,7 @@ import { toast } from '../utils/toast.js'
 import { ref, computed } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 export const useModalStore = defineStore('modal', () => {
   const api = useApi()
@@ -10,6 +11,11 @@ export const useModalStore = defineStore('modal', () => {
   const currentImageId = ref(null)
   const current = ref(null)
   const { loading, error, run } = useAsyncAction({ errorAs: 'message' })
+  // Tag mutations interpolate the image id into the URL after an
+  // await; without an inflight token, a fast prev/next can route the
+  // DELETE/POST to the wrong image AND the response to the wrong
+  // chip rail. Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   // Post-scoped cycle. When set, prev/next cycles within this array
   // (used by PostCard's expanded-mosaic PostImageGrid clicks). When
@@ -19,6 +25,9 @@ export const useModalStore = defineStore('modal', () => {
   const postImageIndex = ref(0)
 
   async function open (id, opts = {}) {
+    // Cancel any in-flight tag mutation or reloadTags from the
+    // previous image so its late response can't apply to this one.
+    inflight.cancel()
     currentImageId.value = id
     current.value = null  // cleared upfront so it stays null on error
     // Update post-scoped state if caller passed it; otherwise clear so
@@ -31,12 +40,16 @@ export const useModalStore = defineStore('modal', () => {
       postImageIds.value = null
       postImageIndex.value = 0
     }
+    const t = inflight.claim()
     await run(async () => {
-      current.value = await api.get(`/api/gallery/image/${id}`)
+      const body = await api.get(`/api/gallery/image/${id}`)
+      if (!t.isCurrent()) return
+      current.value = body
     })
   }
 
   async function close () {
+    inflight.cancel()
     currentImageId.value = null
     current.value = null
     error.value = null
@@ -75,37 +88,87 @@ export const useModalStore = defineStore('modal', () => {
   }
 
   async function reloadTags () {
-    if (!currentImageId.value) return
-    const tags = await api.get(`/api/images/${currentImageId.value}/tags`)
-    if (current.value) current.value.tags = tags
+    // Capture image id at call-time. After an await, currentImageId
+    // may have advanced via prev/next navigation; without capture, the
+    // GET would target the new image and write its tags onto a chip
+    // rail the user didn't open. Audit 2026-06-02.
+    const imageId = currentImageId.value
+    if (!imageId) return
+    const t = inflight.claim()
+    const tags = await api.get(`/api/images/${imageId}/tags`)
+    if (!t.isCurrent()) return
+    // Only commit if the modal is still showing this image — guards
+    // against close() / nav clearing current between the await and now.
+    if (current.value && currentImageId.value === imageId) {
+      current.value.tags = tags
+    }
   }
 
   async function removeTag (tagId) {
-    if (!currentImageId.value) return
+    const imageId = currentImageId.value
+    if (!imageId) return
     const prev = current.value.tags
+    // Optimistic UI: drop the chip immediately.
     current.value.tags = current.value.tags.filter(t => t.id !== tagId)
+    // Split the two POSTs so a dismiss failure (secondary side-effect)
+    // doesn't roll back the successful DELETE — previously the catch
+    // unconditionally restored the chip rail even when only the
+    // dismiss had failed, so the UI lied until refresh. Audit 2026-06-02.
     try {
-      await api.delete(`/api/images/${currentImageId.value}/tags/${tagId}`)
-      await api.post(`/api/images/${currentImageId.value}/suggestions/dismiss`, {
+      await api.delete(`/api/images/${imageId}/tags/${tagId}`)
+    } catch (e) {
+      // Real failure: roll back, surface, rethrow.
+      if (current.value && currentImageId.value === imageId) {
+        current.value.tags = prev
+      }
+      toast({ text: `Failed to remove tag: ${e.message}`, type: 'error' })
+      throw e
+    }
+    // DELETE landed. The dismiss is fire-and-best-effort — log on
+    // failure but DON'T roll back the chip rail; the tag is gone
+    // server-side regardless.
+    try {
+      await api.post(`/api/images/${imageId}/suggestions/dismiss`, {
         body: { tag_id: tagId },
       })
     } catch (e) {
-      current.value.tags = prev
-      toast({ text: `Failed to remove tag: ${e.message}`, type: 'error' })
-      throw e
+      toast({
+        text: `Tag removed, but failed to dismiss suggestion: ${e.message}`,
+        type: 'warning',
+      })
     }
   }
 
   async function addExistingTag (tagId) {
-    if (!currentImageId.value) return
-    await api.post(`/api/images/${currentImageId.value}/tags`, {
+    const imageId = currentImageId.value
+    if (!imageId) return
+    await api.post(`/api/images/${imageId}/tags`, {
       body: { tag_id: tagId, source: 'manual' },
     })
     await reloadTags()
   }
 
   async function createAndAdd ({ name, kind, fandom_id = null }) {
+    // Capture imageId so the post-create reloadTags / addExistingTag
+    // flow stays bound to the image the user clicked on, even if
+    // they navigated during the /api/tags POST.
+    const imageId = currentImageId.value
+    if (!imageId) return
     const tag = await api.post('/api/tags', { body: { name, kind, fandom_id } })
+    // Audit 2026-06-02: a kind='fandom' created here used to be
+    // invisible to FandomPicker until a full page reload — its load
+    // gates on fandomCache.length, so a non-empty cache skips the
+    // refetch and the new fandom never appears. Push it into the
+    // cache directly so the next open sees it.
+    if (kind === 'fandom') {
+      const { useTagStore } = await import('./tags.js')
+      const tagStore = useTagStore()
+      tagStore.fandomCache.push({
+        id: tag.id, name: tag.name, kind: 'fandom',
+        fandom_id: null, fandom_name: null, image_count: 0,
+      })
+    }
+    if (currentImageId.value !== imageId) return  // navigated away
     await addExistingTag(tag.id)
   }
 

frontend/src/stores/posts.js

@@ -2,6 +2,7 @@ import { defineStore } from 'pinia'
 import { ref } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 export const usePostsStore = defineStore('posts', () => {
   const api = useApi()
@@ -19,6 +20,12 @@ export const usePostsStore = defineStore('posts', () => {
   const doneOlder = ref(false)
   const doneNewer = ref(false)
   const anchorId = ref(null)
+  // loadInitial, loadMore, loadAround, loadOlder, loadNewer all share
+  // one `loading` flag and previously had no inflight guard. A filter
+  // change (loadInitial) racing a still-in-flight loadMore would
+  // append the prior filter's items into the new filter's feed.
+  // Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   function _qs() {
     const q = {}
@@ -36,6 +43,7 @@ export const usePostsStore = defineStore('posts', () => {
   }
 
   async function loadInitial(newFilters) {
+    inflight.cancel()
     filters.value = {
       artist_id: newFilters?.artist_id ?? null,
       platform: newFilters?.platform ?? null,
@@ -46,8 +54,10 @@ export const usePostsStore = defineStore('posts', () => {
 
   async function loadMore() {
     if (loading.value || done.value) return
+    const t = inflight.claim()
     await run(async () => {
       const body = await api.get('/api/posts', { params: _qs() })
+      if (!t.isCurrent()) return
       items.value.push(...body.items)
       cursor.value = body.next_cursor
       if (body.next_cursor == null) done.value = true
@@ -59,14 +69,40 @@ export const usePostsStore = defineStore('posts', () => {
     return await api.get(`/api/posts/${id}`)
   }
 
+  // Filter overlay for the around/older/newer (in-context anchored)
+  // path. Keep this distinct from `filters.value` (the down-only feed)
+  // so a normal-feed filter change doesn't leak into an active anchored
+  // view (or vice versa). Caller of loadAround passes the snapshot; the
+  // subsequent loadOlder/loadNewer use it verbatim.
+  function _aroundParams(extra) {
+    const p = { ...extra }
+    if (filters.value.artist_id != null) p.artist_id = filters.value.artist_id
+    if (filters.value.platform) p.platform = filters.value.platform
+    return p
+  }
+
   // Load a window centered on `postId`: newer posts above, the post, older
   // posts below. Sets both directional cursors for subsequent scrolling.
-  async function loadAround(postId) {
+  // Accepts the same filter shape as loadInitial so the anchored view
+  // stays artist/platform-scoped (operator-flagged 2026-06-01: clicking a
+  // post title from the modal's Provenance card opens the post in the
+  // posts feed; without this the older/newer scroll loaded unfiltered
+  // global posts instead of staying in the artist's stream).
+  async function loadAround(postId, newFilters) {
+    inflight.cancel()
+    filters.value = {
+      artist_id: newFilters?.artist_id ?? null,
+      platform: newFilters?.platform ?? null,
+    }
     loading.value = true
     error.value = null
     anchorId.value = null
+    const t = inflight.claim()
     try {
-      const body = await api.get('/api/posts', { params: { around: postId } })
+      const body = await api.get('/api/posts', {
+        params: _aroundParams({ around: postId }),
+      })
+      if (!t.isCurrent()) return
       items.value = body.items
       cursorOlder.value = body.cursor_older
       cursorNewer.value = body.cursor_newer
@@ -74,43 +110,54 @@ export const usePostsStore = defineStore('posts', () => {
       doneNewer.value = body.cursor_newer == null
       anchorId.value = body.anchor_id
     } catch (e) {
+      if (!t.isCurrent()) return
       error.value = e
     } finally {
-      loading.value = false
+      if (t.isCurrent()) loading.value = false
     }
   }
 
   async function loadOlder() {
     if (loading.value || doneOlder.value || cursorOlder.value == null) return
     loading.value = true
+    const t = inflight.claim()
     try {
       const body = await api.get('/api/posts', {
-        params: { cursor: cursorOlder.value, direction: 'older' },
+        params: _aroundParams({
+          cursor: cursorOlder.value, direction: 'older',
+        }),
       })
+      if (!t.isCurrent()) return
       items.value.push(...body.items)
       cursorOlder.value = body.next_cursor
       if (body.next_cursor == null) doneOlder.value = true
     } catch (e) {
+      if (!t.isCurrent()) return
       error.value = e
     } finally {
-      loading.value = false
+      if (t.isCurrent()) loading.value = false
     }
   }
 
   async function loadNewer() {
     if (loading.value || doneNewer.value || cursorNewer.value == null) return
     loading.value = true
+    const t = inflight.claim()
     try {
       const body = await api.get('/api/posts', {
-        params: { cursor: cursorNewer.value, direction: 'newer' },
+        params: _aroundParams({
+          cursor: cursorNewer.value, direction: 'newer',
+        }),
       })
+      if (!t.isCurrent()) return
       items.value.unshift(...body.items)
       cursorNewer.value = body.next_cursor
       if (body.next_cursor == null) doneNewer.value = true
     } catch (e) {
+      if (!t.isCurrent()) return
       error.value = e
     } finally {
-      loading.value = false
+      if (t.isCurrent()) loading.value = false
     }
   }
 

frontend/src/stores/showcase.js

@@ -19,6 +19,16 @@ import { useApi } from '../composables/useApi.js'
 const PAGE = 3
 const INITIAL_BATCHES = 20
 const APPEND_DELAY_MS = 80  // ≈ the MasonryGrid stagger animation (70 ms)
+// Operator-flagged 2026-06-01: scrolling the showcase eventually hit a
+// premature "End." because /api/showcase returns a *random sample* and
+// after enough scrolling the `seen` Set accumulated enough to fully
+// collide with a 3-item batch. The showcase is supposed to be endless;
+// only a genuinely empty API response (library has zero images) should
+// mark it exhausted. Retry up to FETCH_RETRY_CAP times on all-dupe
+// batches; only flip `exhausted` when the API returns 0 items OR every
+// retry came back dupe-only (graceful fallback for tiny libraries
+// where retries will keep returning the same handful of items).
+const FETCH_RETRY_CAP = 8
 
 
 function _sleep(ms) { return new Promise(r => setTimeout(r, ms)) }
@@ -48,17 +58,32 @@ export const useShowcaseStore = defineStore('showcase', () => {
     }
   }
 
-  // Single batch — used by infinite-scroll appends. Trickles its 5 items
-  // in for the same one-at-a-time cadence as the initial load.
+  // Single batch — used by infinite-scroll appends. Trickles its items
+  // in for the same one-at-a-time cadence as the initial load. Retries
+  // up to FETCH_RETRY_CAP times when the API's random sample comes back
+  // all-duplicates (the showcase is endless by design; only a genuinely
+  // empty API response should mark it exhausted, not an unlucky sample).
   async function fetchPage() {
     if (loading.value) return
     loading.value = true
     error.value = null
     try {
-      const body = await api.get('/api/showcase', { params: { limit: PAGE } })
-      const fresh = (body.images || []).filter(i => !seen.has(i.id))
-      if (fresh.length === 0) { exhausted.value = true; return }
-      await _trickleAppend(fresh, _seq)
+      for (let attempt = 0; attempt < FETCH_RETRY_CAP; attempt++) {
+        const body = await api.get('/api/showcase', { params: { limit: PAGE } })
+        const items = body.images || []
+        // API genuinely empty → library is empty / endpoint exhausted.
+        if (items.length === 0) { exhausted.value = true; return }
+        const fresh = items.filter(i => !seen.has(i.id))
+        if (fresh.length > 0) {
+          await _trickleAppend(fresh, _seq)
+          return
+        }
+        // All-dupes batch — keep trying. Showcase is endless by intent.
+      }
+      // Retry cap hit with zero fresh items: library is probably much
+      // smaller than the running `seen` set, fall back to exhausted so
+      // the UI stops trying. Operator can shuffle to reset `seen`.
+      exhausted.value = true
     } catch (e) {
       error.value = e.message || String(e)
     } finally {

frontend/src/stores/sources.js

@@ -85,6 +85,15 @@ export const useSourcesStore = defineStore('sources', () => {
     }
   }
 
+  // Plan #544: arm a source for backfill mode. The next `runs` download
+  // runs (default 3) walk gallery-dl's full post history instead of
+  // exiting early at the first contiguous archived block.
+  async function setBackfill(id, runs = 3, artistIdHint = null) {
+    const body = await api.post(`/api/sources/${id}/backfill`, { body: { runs } })
+    _invalidate(artistIdHint ?? body.artist_id)
+    return body
+  }
+
   function sourcesByArtistGrouped() {
     // returns [{artist: {id,name,slug}, sources: [...]}, ...]
     const arr = byArtist.value.get(null) ?? []
@@ -111,6 +120,7 @@ export const useSourcesStore = defineStore('sources', () => {
     loadAll, loadForArtist,
     create, update, remove,
     checkNow,
+    setBackfill,
     findOrCreateArtist, autocompleteArtist,
     loadScheduleStatus,
     sourcesByArtistGrouped,

frontend/src/stores/suggestions.js

@@ -3,13 +3,14 @@ import { toast } from '../utils/toast.js'
 import { ref } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
-// Category display order: people/sources first, general last.
-export const CATEGORY_ORDER = ['artist', 'character', 'copyright', 'general']
+// Category display order: people first, general last.
+// 'artist' (FC-2d-vii-c) and 'copyright' (2026-06-01) retired — only
+// character and general surface as suggestion categories now.
+export const CATEGORY_ORDER = ['character', 'general']
 export const CATEGORY_LABELS = {
-  artist: 'Artist',
   character: 'Character',
-  copyright: 'Copyright',
   general: 'General'
 }
 
@@ -18,12 +19,25 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
   const byCategory = ref({})       // { category: [suggestion, ...] }
   const { loading, error, run } = useAsyncAction({ errorAs: 'message' })
   let currentImageId = null
+  // Audit 2026-06-02: this store had no inflight guard — a late
+  // /suggestions response from a prior image could overwrite
+  // byCategory while currentImageId pointed at a new one, and
+  // accept() dereferenced currentImageId AFTER an awaited POST so
+  // the subsequent /suggestions/accept could apply A's chosen tag
+  // to image B (and push it to the allowlist). Both fixed below
+  // by capturing imageId at call-time and gating writes on the token.
+  const inflight = useInflightToken()
 
   async function load(imageId) {
+    // Cancel any in-flight load from the previous image so its late
+    // response can't overwrite this image's byCategory.
+    inflight.cancel()
     currentImageId = imageId
     byCategory.value = {}  // cleared upfront so it stays empty on error
+    const t = inflight.claim()
     await run(async () => {
       const body = await api.get(`/api/images/${imageId}/suggestions`)
+      if (!t.isCurrent()) return
       byCategory.value = body.by_category || {}
     })
   }
@@ -35,6 +49,11 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
   }
 
   async function accept(suggestion) {
+    // Capture imageId so a mid-flight prev/next can't reroute the
+    // accept POST to a different image AND push the tag to that
+    // image's allowlist.
+    const imageId = currentImageId
+    if (imageId == null) return
     // Raw tags (creates_new_tag) have no canonical_tag_id; the backend's
     // accept endpoint needs a tag_id, so for raw tags we create the tag
     // first via the existing /api/tags endpoint, then accept by id.
@@ -45,10 +64,14 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
       })
       tagId = created.id
     }
-    await api.post(`/api/images/${currentImageId}/suggestions/accept`, {
+    await api.post(`/api/images/${imageId}/suggestions/accept`, {
       body: { tag_id: tagId }
     })
-    _drop(suggestion.category, s => s === suggestion)
+    // Only drop from THIS image's category list — if the user navigated,
+    // the new image has its own suggestions and this drop would corrupt them.
+    if (currentImageId === imageId) {
+      _drop(suggestion.category, s => s === suggestion)
+    }
     toast({
       text: `Tagged: ${suggestion.display_name}`,
       type: 'success'
@@ -56,14 +79,18 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
   }
 
   async function aliasAccept(suggestion, canonicalTagId) {
-    await api.post(`/api/images/${currentImageId}/suggestions/alias`, {
+    const imageId = currentImageId
+    if (imageId == null) return
+    await api.post(`/api/images/${imageId}/suggestions/alias`, {
       body: {
         alias_string: suggestion.display_name,
         alias_category: suggestion.category,
         canonical_tag_id: canonicalTagId
       }
     })
-    _drop(suggestion.category, s => s === suggestion)
+    if (currentImageId === imageId) {
+      _drop(suggestion.category, s => s === suggestion)
+    }
     toast({
       text: `Aliased & tagged: ${suggestion.display_name}`,
       type: 'success'
@@ -71,15 +98,19 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
   }
 
   async function dismiss(suggestion) {
+    const imageId = currentImageId
+    if (imageId == null) return
     // Dismiss needs a tag_id; raw tags have none, so dismissing a raw
     // suggestion just hides it client-side (nothing to persist a rejection
     // against until the tag exists).
     if (suggestion.canonical_tag_id != null) {
-      await api.post(`/api/images/${currentImageId}/suggestions/dismiss`, {
+      await api.post(`/api/images/${imageId}/suggestions/dismiss`, {
         body: { tag_id: suggestion.canonical_tag_id }
       })
     }
-    _drop(suggestion.category, s => s === suggestion)
+    if (currentImageId === imageId) {
+      _drop(suggestion.category, s => s === suggestion)
+    }
   }
 
   return {

frontend/src/stores/systemActivity.js

@@ -9,7 +9,7 @@ export const useSystemActivityStore = defineStore('systemActivity', () => {
   // Live polled state.
   const queues = ref(null)       // { queues: {name: depth|null}, fetched_at }
   const workers = ref(null)      // { workers: {hostname: {...}}, fetched_at }
-  const recentMinute = ref([])   // last-60s rows (for Overview summary)
+  const recentRuns = ref([])   // last-60s rows (for Overview summary)
   const failures = ref(null)     // { recent, count_by_type, since }
 
   // Paginated runs (Activity tab "All recent activity" pane).
@@ -45,14 +45,14 @@ export const useSystemActivityStore = defineStore('systemActivity', () => {
     }
   }
 
-  async function loadRecentMinute() {
+  async function loadRecentRuns() {
     // Used by the Overview summary card: pull last 60s of runs to compute
     // per-queue ok/err counts. One call covers all queues; UI groups.
     try {
       const body = await api.get('/api/system/activity/runs', {
         params: { limit: 200 },
       })
-      recentMinute.value = body.runs || []
+      recentRuns.value = body.runs || []
     } catch (e) {
       lastError.value = e.message
     }
@@ -106,10 +106,10 @@ export const useSystemActivityStore = defineStore('systemActivity', () => {
   }
 
   return {
-    queues, workers, recentMinute, failures, summary,
+    queues, workers, recentRuns, failures, summary,
     runs, runsCursor, runsHasMore, runsFilter,
     loading, lastError,
-    loadQueues, loadWorkers, loadRecentMinute,
+    loadQueues, loadWorkers, loadRecentRuns,
     loadRuns, loadFailures, loadSummary, setFilter,
   }
 })

frontend/src/stores/tagDirectory.js

@@ -2,6 +2,7 @@ import { defineStore } from 'pinia'
 import { ref, computed } from 'vue'
 import { useApi } from '../composables/useApi.js'
 import { useAsyncAction } from '../composables/useAsyncAction.js'
+import { useInflightToken } from '../composables/useInflightToken.js'
 
 const PAGE = 60
 
@@ -13,16 +14,21 @@ export const useTagDirectoryStore = defineStore('tagDirectory', () => {
   const kind = ref(null)
   const q = ref('')
   let started = false
+  // Same shape as artistDirectory — rapid setQuery/setKind dropped
+  // the second fetch because loading was still true from the first.
+  // Audit 2026-06-02.
+  const inflight = useInflightToken()
 
   async function loadMore() {
-    if (loading.value) return
     if (started && nextCursor.value === null) return
+    const t = inflight.claim()
     await run(async () => {
       const params = { limit: PAGE }
       if (kind.value) params.kind = kind.value
       if (q.value) params.q = q.value
       if (nextCursor.value) params.cursor = nextCursor.value
       const body = await api.get('/api/tags/directory', { params })
+      if (!t.isCurrent()) return
       cards.value.push(...body.cards)
       nextCursor.value = body.next_cursor
       started = true
@@ -30,6 +36,7 @@ export const useTagDirectoryStore = defineStore('tagDirectory', () => {
   }
 
   async function reset() {
+    inflight.cancel()
     cards.value = []
     nextCursor.value = null
     started = false

frontend/src/stores/thumbnails.js

@@ -4,8 +4,11 @@ import { useApi } from '../composables/useApi.js'
 export const useThumbnailsStore = defineStore('thumbnails', () => {
   const api = useApi()
 
+  // Returns { scanned, enqueued, ok, regenerated } — the API now runs
+  // the scan synchronously so the operator gets immediate feedback
+  // instead of just a Celery task id with no visible outcome.
   async function triggerBackfill () {
-    await api.post('/api/thumbnails/backfill')
+    return await api.post('/api/thumbnails/backfill')
   }
 
   return { triggerBackfill }

frontend/src/views/GalleryView.vue

@@ -24,7 +24,7 @@
 
 <script setup>
 import { onMounted, watch } from 'vue'
-import { useRoute, useRouter } from 'vue-router'
+import { useRoute } from 'vue-router'
 import { useGalleryStore } from '../stores/gallery.js'
 import { useModalStore } from '../stores/modal.js'
 import GalleryGrid from '../components/gallery/GalleryGrid.vue'
@@ -37,7 +37,6 @@ import { useGallerySelectionStore } from '../stores/gallerySelection.js'
 const store = useGalleryStore()
 const modal = useModalStore()
 const sel = useGallerySelectionStore()
-const router = useRouter()
 const route = useRoute()
 
 onMounted(async () => {
@@ -47,9 +46,6 @@ onMounted(async () => {
   else if (!isNaN(tagId)) store.setTagFilter(tagId)
   await store.loadInitial()
   await store.loadTimeline()
-  // Open modal if URL has ?image=N
-  const initial = parseInt(route.query.image, 10)
-  if (!isNaN(initial)) modal.open(initial)
 })
 
 watch(() => route.query.tag_id, (q) => {
@@ -64,19 +60,8 @@ watch(() => route.query.post_id, (q) => {
   store.setPostFilter(isNaN(postId) ? null : postId)
 })
 
-watch(() => route.query.image, (q) => {
-  const id = parseInt(q, 10)
-  if (!isNaN(id) && id !== modal.currentImageId) modal.open(id)
-  else if (isNaN(id) && modal.currentImageId !== null) modal.close()
-})
-
 function openImage(id) {
-  router.push({ query: { ...route.query, image: id } })
-}
-function closeImage() {
-  const q = { ...route.query }
-  delete q.image
-  router.push({ query: q })
+  modal.open(id)
 }
 </script>
 

frontend/src/views/PostsView.vue

@@ -161,7 +161,15 @@ function setupAroundObservers() {
 }
 async function loadAroundAndAnchor() {
   teardownFeed()
-  await store.loadAround(postIdFilter.value)
+  // Pass artist_id + platform through so the anchored view stays
+  // scoped — the older/newer infinite scrolls then read these filters
+  // back via the store's _aroundParams (operator-flagged 2026-06-01:
+  // post-title click from the modal landed scoped but the scroll then
+  // pulled unfiltered global posts).
+  await store.loadAround(postIdFilter.value, {
+    artist_id: artistFilter.value,
+    platform: platformFilter.value,
+  })
   await nextTick()
   const el = document.getElementById(`fc-post-${store.anchorId}`)
   if (el) el.scrollIntoView({ block: 'center' })

frontend/src/views/ShowcaseView.vue

@@ -70,7 +70,12 @@ function onKeydown(e) {
 }
 
 onMounted(() => {
-  if (store.images.length === 0) store.loadInitial()
+  // Operator-stated 2026-06-02: every load of the showcase view should
+  // show new images. Pinia persists the store across navigations, so
+  // returning to /showcase used to render the same set as before. Now
+  // we always reshuffle on mount — loadInitial() resets `seen`,
+  // `images`, and `exhausted` and pipelines a fresh batch.
+  store.loadInitial()
   window.addEventListener('keydown', onKeydown)
 })
 onUnmounted(() => window.removeEventListener('keydown', onKeydown))

frontend/test/credentials.spec.js

@@ -27,12 +27,17 @@ describe('credentials store', () => {
     expect(s.byPlatform.get('patreon').credential_type).toBe('cookies')
   })
 
-  it('upload invalidates the cache', async () => {
+  it('upload reflects the returned record into the cache', async () => {
+    // The previous behavior was to delete the cache entry on upload, which
+    // briefly showed "no credential" until a follow-up loadAll() resolved.
+    // Audit 2026-06-02 corrected this: upload now stores the returned
+    // record directly so the card updates immediately.
     const s = useCredentialsStore()
-    s.byPlatform.set('patreon', { platform: 'patreon' })
-    stubFetch(() => ({ status: 201, body: { platform: 'patreon', credential_type: 'cookies' } }))
+    s.byPlatform.set('patreon', { platform: 'patreon', credential_type: 'token' })
+    const fresh = { platform: 'patreon', credential_type: 'cookies' }
+    stubFetch(() => ({ status: 201, body: fresh }))
     await s.upload('patreon', 'cookies', 'NETSCAPE_CONTENT')
-    expect(s.byPlatform.has('patreon')).toBe(false)
+    expect(s.byPlatform.get('patreon')).toEqual(fresh)
   })
 
   it('remove deletes and invalidates the cache', async () => {

tests/conftest.py

@@ -8,18 +8,25 @@ migration code paths.
 
 import os
 
-import pytest
-import pytest_asyncio
-from sqlalchemy import create_engine
-from sqlalchemy.ext.asyncio import (
+# Audit 2026-06-02: CredentialCrypto now refuses to auto-generate a
+# Fernet key without explicit opt-in (production safety against silent
+# key regeneration on partial restore). The test environment never has
+# a pre-seeded key file, so set the bootstrap flag here before any
+# create_app() / CredentialCrypto() import path fires.
+os.environ.setdefault("CURATOR_BOOTSTRAP_NEW_KEY", "1")
+
+import pytest  # noqa: E402
+import pytest_asyncio  # noqa: E402
+from sqlalchemy import create_engine  # noqa: E402
+from sqlalchemy.ext.asyncio import (  # noqa: E402
     AsyncSession,
     async_sessionmaker,
     create_async_engine,
 )
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import sessionmaker  # noqa: E402
 
-from backend.app import create_app
-from backend.app.models import Base
+from backend.app import create_app  # noqa: E402
+from backend.app.models import Base  # noqa: E402
 
 
 def _async_database_url() -> str:

tests/test_api_artist.py

@@ -37,8 +37,8 @@ async def test_artist_overview_post_count(client, db):
     )
     db.add(s)
     await db.flush()
-    db.add(Post(source_id=s.id, external_post_id="p1"))
-    db.add(Post(source_id=s.id, external_post_id="p2"))
+    db.add(Post(source_id=s.id, artist_id=a.id, external_post_id="p1"))
+    db.add(Post(source_id=s.id, artist_id=a.id, external_post_id="p2"))
     await db.flush()
     await db.commit()
     resp = await client.get("/api/artist/lyra")

tests/test_api_extension.py

@@ -135,6 +135,114 @@ async def test_quick_add_source_wrong_key_401(client, ext_key):
     assert resp.status_code == 401
 
 
+# --- /api/extension/probe ---------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_probe_returns_new_when_nothing_exists(client, ext_key):
+    resp = await client.get(
+        "/api/extension/probe",
+        query_string={"url": "https://www.patreon.com/freshcreator"},
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["state"] == "new"
+    assert body["platform"] == "patreon"
+    assert body["slug"] == "freshcreator"
+
+
+@pytest.mark.asyncio
+async def test_probe_returns_source_match_for_already_added(client, ext_key, db):
+    artist = Artist(name="Alice", slug="alice", is_subscription=True)
+    db.add(artist)
+    await db.flush()
+    src = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://www.patreon.com/alice", enabled=True, config_overrides={},
+    )
+    db.add(src)
+    await db.commit()
+
+    resp = await client.get(
+        "/api/extension/probe",
+        query_string={"url": "https://www.patreon.com/alice"},
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["state"] == "source_match"
+    assert body["artist"]["slug"] == "alice"
+    assert body["source"]["url"] == "https://www.patreon.com/alice"
+    assert body["source"]["platform"] == "patreon"
+
+
+@pytest.mark.asyncio
+async def test_probe_returns_artist_match_when_only_synthetic_anchor_exists(
+    client, ext_key, db,
+):
+    """Filesystem-imported artist with only a sidecar synthetic Source
+    for the (artist, platform) — the URL the operator's browsing isn't
+    yet a real Source. The probe should collapse this into artist_match
+    so the chip says '+ Add Patreon source to Dymkens' rather than
+    '+ Add to FabledCurator' (which would re-create the artist)."""
+    artist = Artist(name="Dymkens", slug="dymkens", is_subscription=False)
+    db.add(artist)
+    await db.flush()
+    synthetic = Source(
+        artist_id=artist.id, platform="patreon",
+        url="sidecar:patreon:dymkens", enabled=False, config_overrides={},
+    )
+    db.add(synthetic)
+    await db.commit()
+
+    resp = await client.get(
+        "/api/extension/probe",
+        query_string={"url": "https://www.patreon.com/dymkens"},
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["state"] == "artist_match"
+    assert body["artist"]["slug"] == "dymkens"
+    assert "source" not in body
+
+
+@pytest.mark.asyncio
+async def test_probe_returns_unknown_platform_for_non_artist_url(client, ext_key):
+    """A patreon URL that isn't an artist page (e.g. /home, /posts/N)
+    shouldn't trigger the button. Sentinel 'unknown_platform' state
+    tells the content script to skip injection."""
+    resp = await client.get(
+        "/api/extension/probe",
+        query_string={"url": "https://www.patreon.com/posts/12345"},
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["state"] == "unknown_platform"
+
+
+@pytest.mark.asyncio
+async def test_probe_missing_key_401(client):
+    resp = await client.get(
+        "/api/extension/probe",
+        query_string={"url": "https://www.patreon.com/maewix"},
+    )
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_probe_missing_url_400(client, ext_key):
+    resp = await client.get(
+        "/api/extension/probe",
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 400
+    body = await resp.get_json()
+    assert body["error"] == "invalid_body"
+
+
 @pytest.mark.asyncio
 async def test_quick_add_source_missing_body_400(client, ext_key):
     resp = await client.post(

tests/test_api_ml_admin.py

@@ -19,7 +19,13 @@ async def test_get_and_patch_settings(client):
     resp = await client.get("/api/ml/settings")
     assert resp.status_code == 200
     body = await resp.get_json()
-    assert body["suggestion_threshold_general"] == pytest.approx(0.95)
+    # Default raised 0.50 → 0.70 on 2026-06-02 (alembic 0033) — 0.50
+    # was too noisy in practice. The 0.70 default keeps the rail
+    # signal-rich without hiding everything like the original 0.95.
+    assert body["suggestion_threshold_general"] == pytest.approx(0.70)
+    # Retired threshold columns must not appear in the payload.
+    assert "suggestion_threshold_artist" not in body
+    assert "suggestion_threshold_copyright" not in body
 
     resp = await client.patch(
         "/api/ml/settings", json={"suggestion_threshold_general": 0.90}

tests/test_api_posts.py

@@ -25,7 +25,7 @@ async def seeded_post(db):
     db.add(source)
     await db.flush()
     post = Post(
-        source_id=source.id, external_post_id="API1",
+        source_id=source.id, artist_id=artist.id, external_post_id="API1",
         post_title="Hello", post_url="https://p/alice-api/1",
         post_date=datetime.now(UTC),
         description="<p>hi</p>",
@@ -123,7 +123,8 @@ async def post_timeline(db):
     posts = []
     for i in range(5):
         p = Post(
-            source_id=source.id, external_post_id=f"TL{i}",
+            source_id=source.id, artist_id=artist.id,
+            external_post_id=f"TL{i}",
             post_title=f"post {i}", post_date=base + timedelta(days=i),
         )
         db.add(p)
@@ -189,7 +190,7 @@ async def test_detail_returns_uncapped_thumbnails(client, db):
     db.add(s)
     await db.flush()
     p = Post(
-        source_id=s.id, external_post_id="DETAIL10",
+        source_id=s.id, artist_id=a.id, external_post_id="DETAIL10",
         post_title="big post", description="<p>body</p>",
     )
     db.add(p)

tests/test_api_provenance.py

@@ -26,7 +26,8 @@ async def _seed_full(db):
                     url="https://patreon.test/alice")
     db.add(source)
     await db.flush()
-    post = Post(source_id=source.id, external_post_id="555",
+    post = Post(source_id=source.id, artist_id=artist.id,
+                external_post_id="555",
                 post_url="https://patreon.test/p/555", post_title="Set 1",
                 post_date=datetime(2023, 8, 1, tzinfo=UTC),
                 description="<p>hi</p>", attachment_count=2)

tests/test_api_sources.py

@@ -193,3 +193,61 @@ async def test_list_derives_next_check_at_when_last_checked_set(
     )
     assert target["next_check_at"] is not None
     assert "T" in target["next_check_at"]  # ISO 8601
+
+
+# --- Plan #544: POST /api/sources/{id}/backfill ----------------------------
+
+
+@pytest.mark.asyncio
+async def test_backfill_endpoint_arms_source(client, artist, db):
+    src = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/alice-backfill", enabled=True,
+    )
+    db.add(src)
+    await db.commit()
+    sid = src.id
+
+    resp = await client.post(f"/api/sources/{sid}/backfill", json={"runs": 5})
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["backfill_runs_remaining"] == 5
+
+    # GET reflects the new state.
+    one = await client.get(f"/api/sources/{sid}")
+    assert (await one.get_json())["backfill_runs_remaining"] == 5
+
+
+@pytest.mark.asyncio
+async def test_backfill_endpoint_defaults_to_three(client, artist, db):
+    src = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/alice-backfill-default", enabled=True,
+    )
+    db.add(src)
+    await db.commit()
+    resp = await client.post(f"/api/sources/{src.id}/backfill", json={})
+    body = await resp.get_json()
+    assert body["backfill_runs_remaining"] == 3
+
+
+@pytest.mark.asyncio
+async def test_backfill_endpoint_rejects_out_of_range(client, artist, db):
+    src = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/alice-backfill-bad", enabled=True,
+    )
+    db.add(src)
+    await db.commit()
+    bad = await client.post(f"/api/sources/{src.id}/backfill", json={"runs": 0})
+    assert bad.status_code == 400
+    too_big = await client.post(
+        f"/api/sources/{src.id}/backfill", json={"runs": 99}
+    )
+    assert too_big.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_backfill_endpoint_404_when_source_missing(client):
+    resp = await client.post("/api/sources/999999/backfill", json={"runs": 3})
+    assert resp.status_code == 404

tests/test_api_thumbnails.py

@@ -13,8 +13,16 @@ def eager():
 
 
 @pytest.mark.asyncio
-async def test_trigger_thumbnail_backfill(client):
+async def test_trigger_thumbnail_backfill_returns_counts(client):
+    """The API runs the scan synchronously now and returns
+    {scanned, enqueued, ok, regenerated} — operator-flagged 2026-06-01:
+    the previous fire-and-forget shape returned only a celery_task_id,
+    so the admin UI couldn't show whether backfill found 0 or 5000
+    candidates. \"Found nothing\" was indistinguishable from \"the
+    worker isn't picking up the task.\""""
     r = await client.post("/api/thumbnails/backfill")
-    assert r.status_code == 202
+    assert r.status_code == 200
     body = await r.get_json()
-    assert "celery_task_id" in body
+    assert set(body) == {"scanned", "enqueued", "ok", "regenerated"}
+    for key in ("scanned", "enqueued", "ok", "regenerated"):
+        assert isinstance(body[key], int)

tests/test_artist_service.py

@@ -25,7 +25,7 @@ async def _fixture(db):
     db.add(src)
     await db.flush()
     post = Post(
-        source_id=src.id, external_post_id="p1",
+        source_id=src.id, artist_id=artist.id, external_post_id="p1",
         post_date=datetime(2026, 3, 1, tzinfo=UTC),
     )
     db.add(post)

tests/test_backfill_thumbnails.py

@@ -12,13 +12,16 @@ pytestmark = pytest.mark.integration
 
 def test_thumb_is_valid_jpeg(tmp_path):
     p = tmp_path / "good.jpg"
-    p.write_bytes(b"\xff\xd8\xff\xe0" + b"\x00" * 100)
+    # Real thumbnails are at least ~2KB; size check (MIN_THUMB_BYTES=256)
+    # requires the file body be plausible. 300 bytes here clears the
+    # floor with margin.
+    p.write_bytes(b"\xff\xd8\xff\xe0" + b"\x00" * 300)
     assert _thumb_is_valid(p) is True
 
 
 def test_thumb_is_valid_png(tmp_path):
     p = tmp_path / "good.png"
-    p.write_bytes(b"\x89PNG\r\n\x1a\n" + b"\x00" * 100)
+    p.write_bytes(b"\x89PNG\r\n\x1a\n" + b"\x00" * 300)
     assert _thumb_is_valid(p) is True
 
 
@@ -38,6 +41,16 @@ def test_thumb_is_valid_missing_file(tmp_path):
     assert _thumb_is_valid(tmp_path / "nope") is False
 
 
+def test_thumb_is_valid_header_only_below_min_size(tmp_path):
+    """Operator-flagged 2026-06-01: header-only corrupt files were
+    silently passing the magic-byte check and backfill counted them as
+    `ok`, so the UI's broken-image tiles never got regenerated. Files
+    smaller than MIN_THUMB_BYTES are now invalid even with valid magic."""
+    p = tmp_path / "header_only.jpg"
+    p.write_bytes(b"\xff\xd8\xff\xe0" + b"\x00" * 50)  # 54 bytes total
+    assert _thumb_is_valid(p) is False
+
+
 # --- backfill_thumbnails planner tests ------------------------------------
 
 
@@ -80,13 +93,14 @@ def _rec(db_sync, path, *, sha, thumb_path=None, mime="image/jpeg"):
 
 def _write_jpeg(p: Path) -> Path:
     p.parent.mkdir(parents=True, exist_ok=True)
-    p.write_bytes(b"\xff\xd8\xff\xe0" + b"\x00" * 100)
+    # ≥ MIN_THUMB_BYTES (256) so the size floor doesn't reject it.
+    p.write_bytes(b"\xff\xd8\xff\xe0" + b"\x00" * 300)
     return p
 
 
 def _write_png(p: Path) -> Path:
     p.parent.mkdir(parents=True, exist_ok=True)
-    p.write_bytes(b"\x89PNG\r\n\x1a\n" + b"\x00" * 100)
+    p.write_bytes(b"\x89PNG\r\n\x1a\n" + b"\x00" * 300)
     return p
 
 
@@ -111,7 +125,7 @@ def test_backfill_null_path_enqueued(db_sync, tmp_path, monkeypatch):
     )
 
     result = m.backfill_thumbnails()
-    assert result == {"enqueued": 1, "ok": 0, "regenerated": 0}
+    assert result == {"scanned": 1, "enqueued": 1, "ok": 0, "regenerated": 0}
     assert delayed == [rec.id]
 
 
@@ -134,7 +148,7 @@ def test_backfill_missing_file_clears_and_enqueues(db_sync, tmp_path, monkeypatc
 
     result = m.backfill_thumbnails()
     db_sync.expire_all()
-    assert result == {"enqueued": 1, "ok": 0, "regenerated": 1}
+    assert result == {"scanned": 1, "enqueued": 1, "ok": 0, "regenerated": 1}
     assert delayed == [rec.id]
     assert db_sync.get(ImageRecord, rec.id).thumbnail_path is None
 
@@ -156,7 +170,7 @@ def test_backfill_valid_jpeg_skipped(db_sync, tmp_path, monkeypatch):
 
     result = m.backfill_thumbnails()
     db_sync.expire_all()
-    assert result == {"enqueued": 0, "ok": 1, "regenerated": 0}
+    assert result == {"scanned": 1, "enqueued": 0, "ok": 1, "regenerated": 0}
     assert delayed == []
     assert db_sync.get(ImageRecord, rec.id).thumbnail_path == str(thumb)
 
@@ -177,7 +191,7 @@ def test_backfill_valid_png_skipped(db_sync, tmp_path, monkeypatch):
     )
 
     result = m.backfill_thumbnails()
-    assert result == {"enqueued": 0, "ok": 1, "regenerated": 0}
+    assert result == {"scanned": 1, "enqueued": 0, "ok": 1, "regenerated": 0}
     assert delayed == []
 
 
@@ -198,7 +212,7 @@ def test_backfill_corrupt_magic_clears_and_enqueues(db_sync, tmp_path, monkeypat
 
     result = m.backfill_thumbnails()
     db_sync.expire_all()
-    assert result == {"enqueued": 1, "ok": 0, "regenerated": 1}
+    assert result == {"scanned": 1, "enqueued": 1, "ok": 0, "regenerated": 1}
     assert delayed == [rec.id]
     assert db_sync.get(ImageRecord, rec.id).thumbnail_path is None
 
@@ -238,5 +252,5 @@ def test_backfill_mixed_aggregate(db_sync, tmp_path, monkeypatch):
     )
 
     result = m.backfill_thumbnails()
-    assert result == {"enqueued": 3, "ok": 2, "regenerated": 2}
+    assert result == {"scanned": 5, "enqueued": 3, "ok": 2, "regenerated": 2}
     assert sorted(delayed) == sorted([r_null.id, r_missing.id, r_bad.id])

tests/test_credential_crypto.py

@@ -14,7 +14,7 @@ pytestmark = pytest.mark.integration
 
 def test_load_or_create_writes_key_with_mode_0600(tmp_path):
     key_path = tmp_path / "secrets" / "credential_key.b64"
-    CredentialCrypto(key_path)
+    CredentialCrypto(key_path, bootstrap_ok=True)
     assert key_path.exists()
     mode = stat.S_IMODE(os.stat(key_path).st_mode)
     assert mode == 0o600
@@ -25,9 +25,9 @@ def test_load_or_create_writes_key_with_mode_0600(tmp_path):
 
 def test_load_existing_key_is_idempotent(tmp_path):
     key_path = tmp_path / "credential_key.b64"
-    crypto1 = CredentialCrypto(key_path)
+    crypto1 = CredentialCrypto(key_path, bootstrap_ok=True)
     contents_after_first = key_path.read_bytes()
-    crypto2 = CredentialCrypto(key_path)
+    crypto2 = CredentialCrypto(key_path, bootstrap_ok=True)
     contents_after_second = key_path.read_bytes()
     assert contents_after_first == contents_after_second
     # And both crypto instances decrypt each other's ciphertext
@@ -36,7 +36,7 @@ def test_load_existing_key_is_idempotent(tmp_path):
 
 
 def test_encrypt_decrypt_round_trip(tmp_path):
-    crypto = CredentialCrypto(tmp_path / "k")
+    crypto = CredentialCrypto(tmp_path / "k", bootstrap_ok=True)
     plaintext = "domain.com\tTRUE\t/\tTRUE\t1700000000\tname\tvalue"
     ct = crypto.encrypt(plaintext)
     assert isinstance(ct, bytes)
@@ -45,8 +45,27 @@ def test_encrypt_decrypt_round_trip(tmp_path):
 
 
 def test_decrypt_with_wrong_key_raises(tmp_path):
-    crypto_a = CredentialCrypto(tmp_path / "a")
-    crypto_b = CredentialCrypto(tmp_path / "b")
+    crypto_a = CredentialCrypto(tmp_path / "a", bootstrap_ok=True)
+    crypto_b = CredentialCrypto(tmp_path / "b", bootstrap_ok=True)
     ct = crypto_a.encrypt("secret")
     with pytest.raises(InvalidCredentialBlob):
         crypto_b.decrypt(ct)
+
+
+def test_missing_key_without_bootstrap_raises(tmp_path, monkeypatch):
+    """Audit 2026-06-02: without explicit opt-in, a missing key file
+    is a fatal startup error — silent regeneration on partial restore
+    would make every existing Credential row undecryptable."""
+    from backend.app.services.credential_crypto import MissingCredentialKey
+    monkeypatch.delenv("CURATOR_BOOTSTRAP_NEW_KEY", raising=False)
+    with pytest.raises(MissingCredentialKey):
+        CredentialCrypto(tmp_path / "absent.b64")
+
+
+def test_missing_key_with_env_var_bootstraps(tmp_path, monkeypatch):
+    """The env var CURATOR_BOOTSTRAP_NEW_KEY=1 is the operator's
+    first-time-setup opt-in for auto-creating the key file."""
+    monkeypatch.setenv("CURATOR_BOOTSTRAP_NEW_KEY", "1")
+    key_path = tmp_path / "bootstrap.b64"
+    CredentialCrypto(key_path)  # no bootstrap_ok kwarg — relies on env
+    assert key_path.exists()