diff --git a/backend/app/api/gpu.py b/backend/app/api/gpu.py
index 44a7aac..8ee7bb9 100644
--- a/backend/app/api/gpu.py
+++ b/backend/app/api/gpu.py
@@ -256,9 +256,7 @@ async def lease():
         if not await _agent_authed(session):
             return jsonify({"error": "unauthorized"}), 401
         jobs = await GpuJobService(session).lease(agent_id, batch_size=batch)
-        ml = (
-            await session.execute(select(MLSettings).where(MLSettings.id == 1))
-        ).scalar_one()
+        ml = await MLSettings.load(session)
         # image rows for url/mime in one shot
         ids = [j.image_record_id for j in jobs]
         imgs = {
diff --git a/backend/app/api/ml_admin.py b/backend/app/api/ml_admin.py
index 6afff73..5660090 100644
--- a/backend/app/api/ml_admin.py
+++ b/backend/app/api/ml_admin.py
@@ -4,6 +4,7 @@ from quart import Blueprint, jsonify, request
 
 from ..extensions import get_session
 from ..models import MLSettings
+from ..services.ml.heads import AUTO_APPLY_THRESHOLD_MAX, AUTO_APPLY_THRESHOLD_MIN
 
 ml_admin_bp = Blueprint("ml_admin", __name__, url_prefix="/api/ml")
 
@@ -83,48 +84,21 @@ async def embedder_models():
 
 @ml_admin_bp.route("/settings", methods=["GET"])
 async def get_settings():
-    from sqlalchemy import select
-
     async with get_session() as session:
-        s = (
-            await session.execute(select(MLSettings).where(MLSettings.id == 1))
-        ).scalar_one()
-    return jsonify(
-        {
-            "cpu_embed_enabled": s.cpu_embed_enabled,
-            "video_frame_interval_seconds": s.video_frame_interval_seconds,
-            "video_max_frames": s.video_max_frames,
-            "embedder_model_version": s.embedder_model_version,
-            "head_min_positives": s.head_min_positives,
-            "head_auto_apply_precision": s.head_auto_apply_precision,
-            "head_auto_apply_enabled": s.head_auto_apply_enabled,
-            "head_auto_apply_min_positives": s.head_auto_apply_min_positives,
-            "ccip_match_threshold": s.ccip_match_threshold,
-            "ccip_auto_apply_enabled": s.ccip_auto_apply_enabled,
-            "ccip_auto_apply_threshold": s.ccip_auto_apply_threshold,
-            "presentation_auto_apply_enabled": s.presentation_auto_apply_enabled,
-            "presentation_auto_apply_threshold": s.presentation_auto_apply_threshold,
-            "presentation_conflict_threshold": s.presentation_conflict_threshold,
-            "process_auto_apply_enabled": s.process_auto_apply_enabled,
-            "process_auto_apply_threshold": s.process_auto_apply_threshold,
-            "process_conflict_threshold": s.process_conflict_threshold,
-            "embedder_model_name": s.embedder_model_name,
-            **{f: getattr(s, f) for f in _DETECTOR_FIELDS},
-        }
-    )
+        s = await MLSettings.load(session)
+    # Table-driven off _EDITABLE (which PATCH also writes) so a new settings field
+    # can never be silently absent from GET — the split that historically dropped
+    # fields. _EDITABLE already includes *_DETECTOR_FIELDS.
+    return jsonify({f: getattr(s, f) for f in _EDITABLE})
 
 
 @ml_admin_bp.route("/settings", methods=["PATCH"])
 async def patch_settings():
-    from sqlalchemy import select
-
     body = await request.get_json()
     if not isinstance(body, dict):
         return jsonify({"error": "body must be an object"}), 400
     async with get_session() as session:
-        s = (
-            await session.execute(select(MLSettings).where(MLSettings.id == 1))
-        ).scalar_one()
+        s = await MLSettings.load(session)
 
         # Merge the patch over current values, then validate the result as a
         # whole — the store-floor invariant couples three fields, so they
@@ -154,24 +128,24 @@ def _validate(p: dict) -> str | None:
     # Head training (#114).
     if int(p["head_min_positives"]) < 1:
         return "head_min_positives must be >= 1"
-    if not (0.5 <= float(p["head_auto_apply_precision"]) <= 0.999):
-        return "head_auto_apply_precision must be between 0.5 and 0.999"
+    if not (AUTO_APPLY_THRESHOLD_MIN <= float(p["head_auto_apply_precision"]) <= AUTO_APPLY_THRESHOLD_MAX):
+        return f"head_auto_apply_precision must be between {AUTO_APPLY_THRESHOLD_MIN} and {AUTO_APPLY_THRESHOLD_MAX}"
     if int(p["head_auto_apply_min_positives"]) < 1:
         return "head_auto_apply_min_positives must be >= 1"
-    if not (0.5 <= float(p["ccip_match_threshold"]) <= 0.999):
-        return "ccip_match_threshold must be between 0.5 and 0.999"
-    if not (0.5 <= float(p["ccip_auto_apply_threshold"]) <= 0.999):
-        return "ccip_auto_apply_threshold must be between 0.5 and 0.999"
+    if not (AUTO_APPLY_THRESHOLD_MIN <= float(p["ccip_match_threshold"]) <= AUTO_APPLY_THRESHOLD_MAX):
+        return f"ccip_match_threshold must be between {AUTO_APPLY_THRESHOLD_MIN} and {AUTO_APPLY_THRESHOLD_MAX}"
+    if not (AUTO_APPLY_THRESHOLD_MIN <= float(p["ccip_auto_apply_threshold"]) <= AUTO_APPLY_THRESHOLD_MAX):
+        return f"ccip_auto_apply_threshold must be between {AUTO_APPLY_THRESHOLD_MIN} and {AUTO_APPLY_THRESHOLD_MAX}"
     # Presentation chrome auto-hide (#141). Auto-apply runs high (hiding is
     # consequential); the conflict cut is a plain probability [0,1].
-    if not (0.5 <= float(p["presentation_auto_apply_threshold"]) <= 0.999):
-        return "presentation_auto_apply_threshold must be between 0.5 and 0.999"
+    if not (AUTO_APPLY_THRESHOLD_MIN <= float(p["presentation_auto_apply_threshold"]) <= AUTO_APPLY_THRESHOLD_MAX):
+        return f"presentation_auto_apply_threshold must be between {AUTO_APPLY_THRESHOLD_MIN} and {AUTO_APPLY_THRESHOLD_MAX}"
     if not (0.0 <= float(p["presentation_conflict_threshold"]) <= 1.0):
         return "presentation_conflict_threshold must be between 0 and 1"
     # Process auto-apply (#1464). wip/editor stay VISIBLE so a false apply is
     # low-harm (excludes-from-training + a review flag), but keep the same bar.
-    if not (0.5 <= float(p["process_auto_apply_threshold"]) <= 0.999):
-        return "process_auto_apply_threshold must be between 0.5 and 0.999"
+    if not (AUTO_APPLY_THRESHOLD_MIN <= float(p["process_auto_apply_threshold"]) <= AUTO_APPLY_THRESHOLD_MAX):
+        return f"process_auto_apply_threshold must be between {AUTO_APPLY_THRESHOLD_MIN} and {AUTO_APPLY_THRESHOLD_MAX}"
     if not (0.0 <= float(p["process_conflict_threshold"]) <= 1.0):
         return "process_conflict_threshold must be between 0 and 1"
     # Embedder model swap (#1190): both must be non-empty. Changing them means a
diff --git a/backend/app/api/settings.py b/backend/app/api/settings.py
index d2d916a..ea76989 100644
--- a/backend/app/api/settings.py
+++ b/backend/app/api/settings.py
@@ -66,34 +66,9 @@ _EXTDL_TOGGLE_FIELDS = (
 async def get_import_settings():
     async with get_session() as session:
         row = await ImportSettings.load(session)
-    return jsonify({
-        "min_width": row.min_width,
-        "min_height": row.min_height,
-        "skip_transparent": row.skip_transparent,
-        "transparency_threshold": row.transparency_threshold,
-        "skip_single_color": row.skip_single_color,
-        "single_color_threshold": row.single_color_threshold,
-        "single_color_tolerance": row.single_color_tolerance,
-        "phash_threshold": row.phash_threshold,
-        "download_rate_limit_seconds": row.download_rate_limit_seconds,
-        "download_validate_files": row.download_validate_files,
-        "download_schedule_default_seconds": row.download_schedule_default_seconds,
-        "download_event_retention_days": row.download_event_retention_days,
-        "download_failure_warning_threshold": row.download_failure_warning_threshold,
-        "series_suggest_enabled": row.series_suggest_enabled,
-        "series_suggest_threshold": row.series_suggest_threshold,
-        "extdl_mega_enabled": row.extdl_mega_enabled,
-        "extdl_gdrive_enabled": row.extdl_gdrive_enabled,
-        "extdl_mediafire_enabled": row.extdl_mediafire_enabled,
-        "extdl_dropbox_enabled": row.extdl_dropbox_enabled,
-        "extdl_pixeldrain_enabled": row.extdl_pixeldrain_enabled,
-        "translation_enabled": row.translation_enabled,
-        "interpreter_base_url": row.interpreter_base_url,
-        "translation_target_lang": row.translation_target_lang,
-        "translation_min_confidence": row.translation_min_confidence,
-        "wip_title_tagging_enabled": row.wip_title_tagging_enabled,
-        "wip_soft_title_tagging_enabled": row.wip_soft_title_tagging_enabled,
-    })
+    # Table-driven off _EDITABLE_FIELDS (which PATCH also writes) so a new field
+    # can't be silently absent from GET.
+    return jsonify({f: getattr(row, f) for f in _EDITABLE_FIELDS})
 
 
 @settings_bp.route("/settings/import", methods=["PATCH"])
diff --git a/backend/app/models/ml_settings.py b/backend/app/models/ml_settings.py
index 574d16e..72da17b 100644
--- a/backend/app/models/ml_settings.py
+++ b/backend/app/models/ml_settings.py
@@ -10,6 +10,7 @@ from sqlalchemy import (
     Integer,
     String,
     func,
+    select,
 )
 from sqlalchemy.orm import Mapped, mapped_column
 
@@ -212,3 +213,14 @@ class MLSettings(Base):
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now()
     )
+
+    @classmethod
+    async def load(cls, session) -> MLSettings:
+        """The singleton settings row (id=1), via an async session. Mirrors
+        ImportSettings.load — the shared singleton-loader pattern."""
+        return (await session.execute(select(cls).where(cls.id == 1))).scalar_one()
+
+    @classmethod
+    def load_sync(cls, session) -> MLSettings:
+        """The singleton settings row (id=1), via a sync session."""
+        return session.execute(select(cls).where(cls.id == 1)).scalar_one()
diff --git a/backend/app/services/ml/character_prototypes.py b/backend/app/services/ml/character_prototypes.py
index 7a4802a..821abe9 100644
--- a/backend/app/services/ml/character_prototypes.py
+++ b/backend/app/services/ml/character_prototypes.py
@@ -150,9 +150,7 @@ def refresh_character_prototypes(
     """Incrementally refresh the prototype store. `full=True` rebuilds every
     character regardless of the gate/fingerprints (nightly reconcile). Returns
     {skipped, rebuilt, removed}; commits."""
-    settings = session.execute(
-        select(MLSettings).where(MLSettings.id == 1)
-    ).scalar_one()
+    settings = MLSettings.load_sync(session)
     sig = _global_signature(session)
     if not full and settings.ccip_ref_signature == sig:
         return {"skipped": True, "rebuilt": 0, "removed": 0}
@@ -204,9 +202,7 @@ def retract_auto_applied_ccip(session: Session) -> int:
     n_retracted."""
     import numpy as np
 
-    settings = session.execute(
-        select(MLSettings).where(MLSettings.id == 1)
-    ).scalar_one()
+    settings = MLSettings.load_sync(session)
     if not settings.ccip_auto_apply_enabled:
         return 0
     thr = float(settings.ccip_auto_apply_threshold)
diff --git a/backend/app/services/ml/heads.py b/backend/app/services/ml/heads.py
index ae5e7fc..dbaa8cf 100644
--- a/backend/app/services/ml/heads.py
+++ b/backend/app/services/ml/heads.py
@@ -23,6 +23,7 @@ from datetime import UTC, datetime
 from typing import Any
 
 from sqlalchemy import delete, exists, func, select
+from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import Session
 
@@ -42,6 +43,7 @@ from ...models import (
 from ...models.tag import CHROME_SYSTEM_TAGS, PROCESS_SYSTEM_TAGS, image_tag
 from .training_data import (
     _AUTO_SOURCES,
+    _applied_or_rejected,
     _auto_apply_point,
     _hygiene_excluded_ids,
     _ids_with_tag,
@@ -61,6 +63,14 @@ MIN_POSITIVES_FLOOR = 8     # hard floor; settings.head_min_positives can raise
 _UNLABELED_POOL = 4000
 _EXAMPLES_MIN = 8           # need at least this many embedded +/- to fit a head
 
+# Auto-apply / match confidence operating range. Every graduated auto-apply or
+# CCIP-match threshold the operator can set lives in this band, and the head
+# precision target is clamped to it: below 0.5 "auto-apply" is meaningless, and
+# 1.0 is unachievable so 0.999 is the ceiling. One source shared by the service
+# clamp (_normalize_params) and the API validator (ml_admin._validate).
+AUTO_APPLY_THRESHOLD_MIN = 0.5
+AUTO_APPLY_THRESHOLD_MAX = 0.999
+
 # Only these tag kinds get heads (the surfaced suggestion categories).
 _HEAD_KINDS = (TagKind.general, TagKind.character)
 # tag.kind -> the suggestion category the rail groups under.
@@ -78,6 +88,38 @@ _CATEGORY = {TagKind.general: "general", TagKind.character: "character"}
 _SYSTEM_TAG_SUGGEST_FLOOR = 0.65
 
 
+def _sigmoid(z, np):
+    """Logistic sigmoid 1/(1+e^-z): the head score→probability transform. One home
+    for what was inlined at every scoring site (suggest, both sweeps, retract)."""
+    return 1.0 / (1.0 + np.exp(-z))
+
+
+def _conflict_scores(Xn, Wc, bc, np):
+    """The presentation conflict signal (#141): per row, the MAX content-head
+    probability and WHICH head produced it. Shared by the system-tag sweep's guard-2
+    and the soft-wip audit — both ask "does this ALSO look like real content?"."""
+    cprobs = _sigmoid(Xn @ Wc.T + bc, np)
+    return cprobs.max(axis=1), cprobs.argmax(axis=1)
+
+
+def _insert_presentation_review(
+    session, *, image_record_id, tag_id, conflict_tag_id, conflict_score, mode,
+):
+    """Single-source the ring-loud PresentationReview row shape so the two writers
+    (system-tag sweep guard-2 + soft-wip audit) can't drift on columns or `mode` —
+    they share the (image_record_id, tag_id) composite PK, so a divergent `mode`
+    would be a silent first-writer-wins bug."""
+    session.execute(
+        pg_insert(PresentationReview)
+        .values(
+            image_record_id=image_record_id, tag_id=tag_id,
+            conflict_tag_id=conflict_tag_id, conflict_score=conflict_score,
+            mode=mode,
+        )
+        .on_conflict_do_nothing()
+    )
+
+
 class HeadTrainingAlreadyRunning(Exception):
     """Raised by start_head_training_run when a run is already in flight."""
 
@@ -103,9 +145,7 @@ def start_head_training_run(session: Session, params: dict[str, Any]) -> int:
 
 
 def _settings(session: Session) -> MLSettings:
-    return session.execute(
-        select(MLSettings).where(MLSettings.id == 1)
-    ).scalar_one()
+    return MLSettings.load_sync(session)
 
 
 def _normalize_params(session: Session, params: dict[str, Any] | None) -> dict[str, Any]:
@@ -124,7 +164,7 @@ def _normalize_params(session: Session, params: dict[str, Any] | None) -> dict[s
     except (TypeError, ValueError):
         cv_folds = DEFAULT_CV_FOLDS
     try:
-        precision_target = min(max(float(params.get("precision_target", s.head_auto_apply_precision)), 0.5), 0.999)
+        precision_target = min(max(float(params.get("precision_target", s.head_auto_apply_precision)), AUTO_APPLY_THRESHOLD_MIN), AUTO_APPLY_THRESHOLD_MAX)
     except (TypeError, ValueError):
         precision_target = s.head_auto_apply_precision
     return {
@@ -536,7 +576,7 @@ async def score_image(
     norms[norms == 0] = 1.0
     Xn = X / norms
     Z = Xn @ heads["W"].T + heads["b"]                  # (B, H)
-    probs_bag = 1.0 / (1.0 + np.exp(-Z))                # (B, H)
+    probs_bag = _sigmoid(Z, np)                         # (B, H)
     probs = probs_bag.max(axis=0)                       # (H,) best over the bag
     # ARGMAX beside the max: WHICH bag row won each head → the region that grounds
     # the tag (bag_meta[win]); None when the whole-image vector won (#1206).
@@ -614,9 +654,7 @@ async def ground_applied_tag(
 
 
 async def _settings_async(session: AsyncSession) -> MLSettings:
-    return (
-        await session.execute(select(MLSettings).where(MLSettings.id == 1))
-    ).scalar_one()
+    return await MLSettings.load(session)
 
 
 # --- Earned auto-apply (sync, ml worker) ---------------------------------
@@ -687,7 +725,6 @@ def auto_apply_sweep(
     embeddings in chunks; commits per chunk on a real run. Returns
     {n_applied, concepts:[{tag_id,name,applied,scanned,threshold}]}."""
     import numpy as np
-    from sqlalchemy.dialects.postgresql import insert as pg_insert
 
     settings = _settings(session)
     rows = _auto_apply_heads(
@@ -704,18 +741,7 @@ def auto_apply_sweep(
     names = [r.name for r in rows]
 
     # Skip images that already carry, or have rejected, each tag.
-    skip = {tid: set() for tid in tag_ids}
-    for tid in tag_ids:
-        for (iid,) in session.execute(
-            select(image_tag.c.image_record_id).where(image_tag.c.tag_id == tid)
-        ):
-            skip[tid].add(iid)
-        for (iid,) in session.execute(
-            select(TagSuggestionRejection.image_record_id).where(
-                TagSuggestionRejection.tag_id == tid
-            )
-        ):
-            skip[tid].add(iid)
+    skip = _applied_or_rejected(session, tag_ids)
 
     applied = [0] * len(rows)
     scanned = 0
@@ -729,7 +755,7 @@ def auto_apply_sweep(
         if not cids:
             continue
         Xn = _l2norm(np.vstack([emb[i] for i in cids]).astype(np.float32), np)
-        probs = 1.0 / (1.0 + np.exp(-(Xn @ W.T + b)))   # (N, H)
+        probs = _sigmoid(Xn @ W.T + b, np)              # (N, H)
         scanned += len(cids)
         for h in range(len(rows)):
             tid = tag_ids[h]
@@ -840,7 +866,6 @@ def system_tag_auto_apply_sweep(
     enabled flag is set. numpy-only (no sklearn). Returns {n_applied, n_flagged,
     concepts}."""
     import numpy as np
-    from sqlalchemy.dialects.postgresql import insert as pg_insert
 
     cfg = _SWEEP_MODES[mode]
     settings = _settings(session)
@@ -869,18 +894,7 @@ def system_tag_auto_apply_sweep(
     valued = _valued_image_ids(session)
 
     # Skip images that already carry, or have rejected, each presentation tag.
-    skip = {tid: set() for tid in pres_tag_ids}
-    for tid in pres_tag_ids:
-        for (iid,) in session.execute(
-            select(image_tag.c.image_record_id).where(image_tag.c.tag_id == tid)
-        ):
-            skip[tid].add(iid)
-        for (iid,) in session.execute(
-            select(TagSuggestionRejection.image_record_id).where(
-                TagSuggestionRejection.tag_id == tid
-            )
-        ):
-            skip[tid].add(iid)
+    skip = _applied_or_rejected(session, pres_tag_ids)
 
     applied = [0] * len(pres)
     n_flagged = 0
@@ -895,11 +909,9 @@ def system_tag_auto_apply_sweep(
         if not cids:
             continue
         Xn = _l2norm(np.vstack([emb[i] for i in cids]).astype(np.float32), np)
-        probs = 1.0 / (1.0 + np.exp(-(Xn @ Wp.T + bp)))       # (N, P)
+        probs = _sigmoid(Xn @ Wp.T + bp, np)                  # (N, P)
         if Wc is not None:
-            cprobs = 1.0 / (1.0 + np.exp(-(Xn @ Wc.T + bc)))  # (N, C)
-            max_c = cprobs.max(axis=1)
-            arg_c = cprobs.argmax(axis=1)
+            max_c, arg_c = _conflict_scores(Xn, Wc, bc, np)   # (N,), (N,)
         scanned += len(cids)
         for p in range(len(pres)):
             tid = pres_tag_ids[p]
@@ -924,15 +936,12 @@ def system_tag_auto_apply_sweep(
                 if Wc is not None and float(max_c[idx]) >= conflict_thr:
                     n_flagged += 1
                     if not dry_run:
-                        session.execute(
-                            pg_insert(PresentationReview)
-                            .values(
-                                image_record_id=iid, tag_id=tid,
-                                conflict_tag_id=conf_tag_ids[int(arg_c[idx])],
-                                conflict_score=float(max_c[idx]),
-                                mode=mode,
-                            )
-                            .on_conflict_do_nothing()
+                        _insert_presentation_review(
+                            session,
+                            image_record_id=iid, tag_id=tid,
+                            conflict_tag_id=conf_tag_ids[int(arg_c[idx])],
+                            conflict_score=float(max_c[idx]),
+                            mode=mode,
                         )
         if not dry_run:
             session.commit()
@@ -956,7 +965,6 @@ def soft_wip_conflict_audit(session: Session, dry_run: bool = False) -> dict:
     NOT remove the tag; the operator decides. No-op when there are no content heads.
     numpy-only. Returns {n_scanned, n_flagged}."""
     import numpy as np
-    from sqlalchemy.dialects.postgresql import insert as pg_insert
 
     from ..wip_title import WIP_TITLE_SOFT_SOURCE, resolve_wip_tag_id
 
@@ -993,22 +1001,17 @@ def soft_wip_conflict_audit(session: Session, dry_run: bool = False) -> dict:
             continue
         scanned += len(cids)
         Xn = _l2norm(np.vstack([emb[i] for i in cids]).astype(np.float32), np)
-        cprobs = 1.0 / (1.0 + np.exp(-(Xn @ Wc.T + bc)))
-        max_c = cprobs.max(axis=1)
-        arg_c = cprobs.argmax(axis=1)
+        max_c, arg_c = _conflict_scores(Xn, Wc, bc, np)
         for k in range(len(cids)):
             if float(max_c[k]) >= conflict_thr:
                 n_flagged += 1
                 if not dry_run:
-                    session.execute(
-                        pg_insert(PresentationReview)
-                        .values(
-                            image_record_id=cids[k], tag_id=wip_id,
-                            conflict_tag_id=conf_tag_ids[int(arg_c[k])],
-                            conflict_score=float(max_c[k]),
-                            mode="process",
-                        )
-                        .on_conflict_do_nothing()
+                    _insert_presentation_review(
+                        session,
+                        image_record_id=cids[k], tag_id=wip_id,
+                        conflict_tag_id=conf_tag_ids[int(arg_c[k])],
+                        conflict_score=float(max_c[k]),
+                        mode="process",
                     )
         if not dry_run:
             session.commit()
@@ -1062,7 +1065,7 @@ def retract_auto_applied_heads(session: Session) -> int:
             continue
         Xn = _l2norm(np.vstack([emb[i] for i in cids]).astype(np.float32), np)
         w = np.asarray(weights, dtype=np.float32)
-        probs = 1.0 / (1.0 + np.exp(-(Xn @ w + float(bias))))
+        probs = _sigmoid(Xn @ w + float(bias), np)
         below = [cids[k] for k in np.where(probs < float(thr))[0]]
         for iid in below:
             session.execute(
diff --git a/backend/app/services/ml/training_data.py b/backend/app/services/ml/training_data.py
index b88ebbd..bce0e58 100644
--- a/backend/app/services/ml/training_data.py
+++ b/backend/app/services/ml/training_data.py
@@ -94,6 +94,24 @@ def _rejected_ids(session: Session, tag_id: int) -> list[int]:
     ]
 
 
+def _applied_or_rejected(session: Session, tag_ids) -> dict[int, set[int]]:
+    """Per-tag skip set for the auto-apply sweeps: every image that ALREADY carries
+    the tag (ANY source — not just training positives) OR has rejected it. A sweep
+    never re-applies to these. Shared by auto_apply_sweep + system_tag_auto_apply_sweep
+    (heads.py) and scheduled_ccip_auto_apply (tasks/ml.py). Callers mutate the returned
+    sets in-place to also dedupe within a single run."""
+    skip: dict[int, set[int]] = {}
+    for tid in tag_ids:
+        ids = {
+            r[0] for r in session.execute(
+                select(image_tag.c.image_record_id).where(image_tag.c.tag_id == tid)
+            ).all()
+        }
+        ids.update(_rejected_ids(session, tid))
+        skip[tid] = ids
+    return skip
+
+
 def _sample_unlabeled(session: Session, exclude: set[int], limit: int) -> list[int]:
     """Random image ids (with an embedding) NOT carrying the tag. Concepts are
     sparse, so an untagged image is almost always a true negative."""
diff --git a/backend/app/services/patreon_resolver.py b/backend/app/services/patreon_resolver.py
index f4dc3ef..b4e9300 100644
--- a/backend/app/services/patreon_resolver.py
+++ b/backend/app/services/patreon_resolver.py
@@ -91,48 +91,46 @@ def _sync_lookup(vanity: str, cookies_path: str | None) -> str | None:
     )
 
 
-def _lookup_via_api(vanity: str, cookies_path: str | None) -> str | None:
+def _campaigns_api_first(vanity: str, cookies_path: str | None) -> dict | None:
+    """The first `data` object from Patreon's campaigns API filtered by vanity
+    (`?filter[vanity]=<vanity>&fields[campaign]=name`), or None on any failure
+    (network / non-200 / non-JSON / empty). The single request shape shared by
+    _lookup_via_api (plucks the campaign id) and resolve_display_name (plucks the
+    display name)."""
     jar = _load_cookie_jar(cookies_path)
-    headers = {
-        "User-Agent": _USER_AGENT,
-        "Accept": "application/vnd.api+json",
-    }
-    params = {
-        "filter[vanity]": vanity,
-        "fields[campaign]": "name",
-    }
     try:
         resp = requests.get(
             _CAMPAIGNS_URL,
-            params=params,
-            headers=headers,
+            params={"filter[vanity]": vanity, "fields[campaign]": "name"},
+            headers={"User-Agent": _USER_AGENT, "Accept": "application/vnd.api+json"},
             cookies=jar,
             timeout=_TIMEOUT_SECONDS,
         )
     except requests.RequestException as exc:
         log.warning("Patreon campaigns API request failed for vanity=%s: %s", vanity, exc)
         return None
-
     if resp.status_code != 200:
         log.warning(
             "Patreon campaigns API returned HTTP %d for vanity=%s",
             resp.status_code, vanity,
         )
         return None
-
     try:
         payload = resp.json()
     except ValueError as exc:
         log.warning("Patreon campaigns API returned non-JSON for vanity=%s: %s", vanity, exc)
         return None
+    data = payload.get("data") if isinstance(payload, dict) else None
+    if not isinstance(data, list) or not data or not isinstance(data[0], dict):
+        return None
+    return data[0]
 
-    if not isinstance(payload, dict):
+
+def _lookup_via_api(vanity: str, cookies_path: str | None) -> str | None:
+    first = _campaigns_api_first(vanity, cookies_path)
+    if first is None:
         return None
-    data = payload.get("data")
-    if not isinstance(data, list) or not data:
-        return None
-    first = data[0] if isinstance(data[0], dict) else None
-    campaign_id = first.get("id") if first else None
+    campaign_id = first.get("id")
     if not isinstance(campaign_id, str) or not campaign_id:
         return None
     log.info("Resolved Patreon vanity=%s → campaign_id=%s", vanity, campaign_id)
@@ -144,24 +142,10 @@ def resolve_display_name(vanity: str, cookies_path: str | None) -> str | None:
     (`fields[campaign]=name`), used to name the Artist at add-time (#130). None
     on any failure — the caller falls back to the vanity handle. Sync: call from
     an executor."""
-    jar = _load_cookie_jar(cookies_path)
-    try:
-        resp = requests.get(
-            _CAMPAIGNS_URL,
-            params={"filter[vanity]": vanity, "fields[campaign]": "name"},
-            headers={"User-Agent": _USER_AGENT, "Accept": "application/vnd.api+json"},
-            cookies=jar,
-            timeout=_TIMEOUT_SECONDS,
-        )
-        if resp.status_code != 200:
-            return None
-        data = resp.json().get("data")
-    except (requests.RequestException, ValueError) as exc:
-        log.warning("Patreon name lookup failed for vanity=%s: %s", vanity, exc)
+    first = _campaigns_api_first(vanity, cookies_path)
+    if first is None:
         return None
-    if not isinstance(data, list) or not data or not isinstance(data[0], dict):
-        return None
-    name = (data[0].get("attributes") or {}).get("name")
+    name = (first.get("attributes") or {}).get("name")
     return name.strip() if isinstance(name, str) and name.strip() else None
 
 
diff --git a/backend/app/tasks/maintenance.py b/backend/app/tasks/maintenance.py
index 2ad0b3f..67432c2 100644
--- a/backend/app/tasks/maintenance.py
+++ b/backend/app/tasks/maintenance.py
@@ -776,89 +776,62 @@ def recover_stalled_library_audit_runs() -> int:
         return recovered
 
 
+def _recover_stalled_runs(model, *, stall_minutes: int, keep_runs: int, label: str) -> int:
+    """Shared recovery + retention sweep for the head run-tracking tables
+    (HeadTrainingRun / HeadAutoApplyRun, which share the
+    status/last_progress_at/started_at/finished_at/error/id columns): flip 'running'
+    rows with no progress past `stall_minutes` to 'error', then prune to the last
+    `keep_runs` (rule 89). Returns the number recovered. NOTE the two other recover
+    tasks are deliberately NOT folded in — library-audit has no prune tail and
+    backup uses a single started_at cutoff."""
+    SessionLocal = _sync_session_factory()
+    now = datetime.now(UTC)
+    cutoff = now - timedelta(minutes=stall_minutes)
+    with SessionLocal() as session:
+        result = session.execute(
+            update(model)
+            .where(model.status == "running")
+            .where(func.coalesce(model.last_progress_at, model.started_at) < cutoff)
+            .values(
+                status="error", finished_at=now,
+                error=f"stranded by recovery sweep (no progress for {stall_minutes} min)",
+            )
+        )
+        keep = session.execute(
+            select(model.id).order_by(model.id.desc()).limit(keep_runs)
+        ).scalars().all()
+        if keep:
+            session.execute(delete(model).where(model.id.not_in(keep)))
+        session.commit()
+        recovered = result.rowcount or 0
+        if recovered:
+            log.info("%s: recovered %d rows", label, recovered)
+        return recovered
+
+
 @celery.task(name="backend.app.tasks.maintenance.recover_stalled_head_training_runs")
 def recover_stalled_head_training_runs() -> int:
     """Flip HeadTrainingRun rows stuck in 'running' past the stall threshold to
     'error', and prune old runs to the last HEAD_TRAINING_KEEP_RUNS (retention,
     rule 89). Runs every 5 min on the maintenance lane; no-op when idle."""
-    SessionLocal = _sync_session_factory()
-    now = datetime.now(UTC)
-    cutoff = now - timedelta(minutes=HEAD_TRAINING_STALL_THRESHOLD_MINUTES)
-    with SessionLocal() as session:
-        result = session.execute(
-            update(HeadTrainingRun)
-            .where(HeadTrainingRun.status == "running")
-            .where(
-                func.coalesce(
-                    HeadTrainingRun.last_progress_at, HeadTrainingRun.started_at
-                )
-                < cutoff
-            )
-            .values(
-                status="error", finished_at=now,
-                error=(
-                    f"stranded by recovery sweep (no progress for "
-                    f"{HEAD_TRAINING_STALL_THRESHOLD_MINUTES} min)"
-                ),
-            )
-        )
-        keep = session.execute(
-            select(HeadTrainingRun.id).order_by(HeadTrainingRun.id.desc())
-            .limit(HEAD_TRAINING_KEEP_RUNS)
-        ).scalars().all()
-        if keep:
-            session.execute(
-                delete(HeadTrainingRun).where(HeadTrainingRun.id.not_in(keep))
-            )
-        session.commit()
-        recovered = result.rowcount or 0
-        if recovered:
-            log.info(
-                "recover_stalled_head_training_runs: recovered %d rows", recovered
-            )
-        return recovered
+    return _recover_stalled_runs(
+        HeadTrainingRun,
+        stall_minutes=HEAD_TRAINING_STALL_THRESHOLD_MINUTES,
+        keep_runs=HEAD_TRAINING_KEEP_RUNS,
+        label="recover_stalled_head_training_runs",
+    )
 
 
 @celery.task(name="backend.app.tasks.maintenance.recover_stalled_head_auto_apply_runs")
 def recover_stalled_head_auto_apply_runs() -> int:
     """Flip stalled HeadAutoApplyRun 'running' rows to 'error' + prune to the
     last HEAD_AUTO_APPLY_KEEP_RUNS (retention, rule 89). 5-min maintenance lane."""
-    SessionLocal = _sync_session_factory()
-    now = datetime.now(UTC)
-    cutoff = now - timedelta(minutes=HEAD_AUTO_APPLY_STALL_THRESHOLD_MINUTES)
-    with SessionLocal() as session:
-        result = session.execute(
-            update(HeadAutoApplyRun)
-            .where(HeadAutoApplyRun.status == "running")
-            .where(
-                func.coalesce(
-                    HeadAutoApplyRun.last_progress_at, HeadAutoApplyRun.started_at
-                )
-                < cutoff
-            )
-            .values(
-                status="error", finished_at=now,
-                error=(
-                    f"stranded by recovery sweep (no progress for "
-                    f"{HEAD_AUTO_APPLY_STALL_THRESHOLD_MINUTES} min)"
-                ),
-            )
-        )
-        keep = session.execute(
-            select(HeadAutoApplyRun.id).order_by(HeadAutoApplyRun.id.desc())
-            .limit(HEAD_AUTO_APPLY_KEEP_RUNS)
-        ).scalars().all()
-        if keep:
-            session.execute(
-                delete(HeadAutoApplyRun).where(HeadAutoApplyRun.id.not_in(keep))
-            )
-        session.commit()
-        recovered = result.rowcount or 0
-        if recovered:
-            log.info(
-                "recover_stalled_head_auto_apply_runs: recovered %d rows", recovered
-            )
-        return recovered
+    return _recover_stalled_runs(
+        HeadAutoApplyRun,
+        stall_minutes=HEAD_AUTO_APPLY_STALL_THRESHOLD_MINUTES,
+        keep_runs=HEAD_AUTO_APPLY_KEEP_RUNS,
+        label="recover_stalled_head_auto_apply_runs",
+    )
 
 
 # Keep ~6 months of daily head-metric snapshots (enough to see tuning trends).
diff --git a/backend/app/tasks/ml.py b/backend/app/tasks/ml.py
index f25d0fe..958b57c 100644
--- a/backend/app/tasks/ml.py
+++ b/backend/app/tasks/ml.py
@@ -105,9 +105,7 @@ def embed_image(self, image_id: int) -> dict:
             record = session.get(ImageRecord, image_id)
             if record is None:
                 return {"status": "missing", "image_id": image_id}
-            settings = session.execute(
-                select(MLSettings).where(MLSettings.id == 1)
-            ).scalar_one()
+            settings = MLSettings.load_sync(session)
 
             src = Path(record.path)
             is_vid = _is_video(src)
@@ -488,15 +486,10 @@ def scheduled_ccip_auto_apply() -> str:
     from sqlalchemy import select as sa_select
     from sqlalchemy.dialects.postgresql import insert as pg_insert
 
-    from ..models import ImageRegion, MLSettings, Tag, TagKind, TagSuggestionRejection
+    from ..models import ImageRegion, MLSettings, Tag, TagKind
     from ..models.tag import image_tag
-
-    fig = ("face", "figure")
-
-    def _l2(m):
-        n = np.linalg.norm(m, axis=1, keepdims=True)
-        n[n == 0] = 1.0
-        return m / n
+    from ..services.ml.ccip import _FIGURE_KINDS
+    from ..services.ml.training_data import _applied_or_rejected, _l2norm
 
     SessionLocal = _sync_session_factory()
     with SessionLocal() as session:
@@ -521,7 +514,7 @@ def scheduled_ccip_auto_apply() -> str:
             )
             .join(Tag, Tag.id == image_tag.c.tag_id)
             .where(Tag.kind == TagKind.character)
-            .where(ImageRegion.kind.in_(fig))
+            .where(ImageRegion.kind.in_(_FIGURE_KINDS))
             .where(ImageRegion.ccip_embedding.is_not(None))
             .where(ImageRegion.image_record_id.in_(single))
         ).all()
@@ -532,29 +525,16 @@ def scheduled_ccip_auto_apply() -> str:
         for tid, vec in ref_rows:
             by_char.setdefault(tid, []).append(vec)
         ref_tags = list(by_char)
-        mats = [_l2(np.asarray(by_char[t], dtype=np.float32)) for t in ref_tags]
+        mats = [_l2norm(np.asarray(by_char[t], dtype=np.float32), np) for t in ref_tags]
         allref = np.vstack(mats)                                  # (total, 768)
         seg = np.cumsum([0] + [len(m) for m in mats])[:-1]        # per-char start
 
         # Per character: images that already carry OR rejected the tag — skip.
-        skip = {t: set() for t in ref_tags}
-        for t in ref_tags:
-            for (iid,) in session.execute(
-                sa_select(image_tag.c.image_record_id).where(
-                    image_tag.c.tag_id == t
-                )
-            ):
-                skip[t].add(iid)
-            for (iid,) in session.execute(
-                sa_select(TagSuggestionRejection.image_record_id).where(
-                    TagSuggestionRejection.tag_id == t
-                )
-            ):
-                skip[t].add(iid)
+        skip = _applied_or_rejected(session, ref_tags)
 
         img_ids = list(session.execute(
             sa_select(ImageRegion.image_record_id)
-            .where(ImageRegion.kind.in_(fig), ImageRegion.ccip_embedding.is_not(None))
+            .where(ImageRegion.kind.in_(_FIGURE_KINDS), ImageRegion.ccip_embedding.is_not(None))
             .distinct()
         ).scalars())
 
@@ -566,7 +546,7 @@ def scheduled_ccip_auto_apply() -> str:
                 sa_select(ImageRegion.image_record_id, ImageRegion.ccip_embedding)
                 .where(
                     ImageRegion.image_record_id.in_(chunk),
-                    ImageRegion.kind.in_(fig),
+                    ImageRegion.kind.in_(_FIGURE_KINDS),
                     ImageRegion.ccip_embedding.is_not(None),
                 )
             ).all()
@@ -574,7 +554,7 @@ def scheduled_ccip_auto_apply() -> str:
             for iid, vec in rows:
                 by_img.setdefault(iid, []).append(vec)
             for iid, vecs in by_img.items():
-                q = _l2(np.asarray(vecs, dtype=np.float32))      # (nq, 768)
+                q = _l2norm(np.asarray(vecs, dtype=np.float32), np)  # (nq, 768)
                 colmax = (q @ allref.T).max(axis=0)              # (total,)
                 charmax = np.maximum.reduceat(colmax, seg)       # (n_chars,)
                 for ci in np.where(charmax >= thr)[0]:
diff --git a/extension/background/background.js b/extension/background/background.js
index e3e3bc7..9fc8f59 100644
--- a/extension/background/background.js
+++ b/extension/background/background.js
@@ -60,9 +60,8 @@ async function checkForUpdateInfo() {
   }
   const currentVersion = browser.runtime.getManifest().version;
   const latestVersion = info && info.version ? info.version : null;
-  // latest_url is served from the web root; strip the /api suffix off baseUrl
-  // (same transform as OPEN_ARTIST_PAGE).
-  const base = (api.baseUrl || '').replace(/\/+$/, '').replace(/\/api$/, '');
+  // latest_url is served from the web root, not the JSON API.
+  const base = api.webRoot();
   return {
     updateAvailable: !!latestVersion && versionIsNewer(latestVersion, currentVersion),
     currentVersion,
@@ -211,6 +210,21 @@ browser.webRequest.onBeforeRedirect.addListener(
   { urls: ['https://app-api.pixiv.net/web/v1/users/auth/pixiv/callback*'] },
 );
 
+// Extract → verify → upload one cookie-auth platform. Returns a structured
+// outcome so the two callers (EXPORT_COOKIES single, EXPORT_ALL_COOKIES) shape
+// their own response + skip semantics. Verifies the captured cookies are
+// actually live BEFORE uploading, so a confirmed-stale session doesn't overwrite
+// good FC-side credentials; platforms with no verify config (v.ok === null) fall
+// through to upload.
+async function exportPlatformCookies(key) {
+  const cookies = await extractCookiesForPlatform(key);
+  if (cookies.length === 0) return { status: 'empty' };
+  const v = await verifyCookiesForPlatform(key);
+  if (v.ok === false) return { status: 'stale', reason: v.reason, cookieCount: cookies.length };
+  await api.uploadCredentials(key, 'cookies', toNetscapeFormat(cookies));
+  return { status: 'ok', cookieCount: cookies.length, verified: v.ok === true };
+}
+
 // ---- Message router ----
 
 browser.runtime.onMessage.addListener(async (msg) => {
@@ -255,22 +269,14 @@ browser.runtime.onMessage.addListener(async (msg) => {
       if (!platform) return { error: `Unknown platform: ${key}` };
       try {
         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) {
+          const r = await exportPlatformCookies(key);
+          if (r.status === 'empty') return { error: 'No cookies found — log in first.' };
+          if (r.status === 'stale') {
             return {
-              error: `Captured ${cookies.length} ${platform.name} cookies but they don't appear authenticated (${v.reason}). Log in again in this browser, then retry.`,
+              error: `Captured ${r.cookieCount} ${platform.name} cookies but they don't appear authenticated (${r.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, verified: v.ok === true };
+          return { success: true, cookieCount: r.cookieCount, verified: r.verified };
         }
         if (key === 'discord') {
           if (!discordToken) return { error: 'Open discord.com to capture a token first.' };
@@ -298,18 +304,10 @@ browser.runtime.onMessage.addListener(async (msg) => {
           continue;
         }
         try {
-          const cookies = await extractCookiesForPlatform(key);
-          if (cookies.length === 0) {
-            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, verified: v.ok === true };
+          const r = await exportPlatformCookies(key);
+          if (r.status === 'empty') results[key] = { skipped: true, reason: 'no cookies' };
+          else if (r.status === 'stale') results[key] = { error: `verify failed: ${r.reason}` };
+          else results[key] = { success: true, cookieCount: r.cookieCount, verified: r.verified };
         } catch (e) {
           results[key] = { error: e.message };
         }
@@ -346,11 +344,9 @@ browser.runtime.onMessage.addListener(async (msg) => {
       }
 
     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(/\/+$/, '').replace(/\/api$/, '');
+      // The SPA artist route (/artist/:slug) is served from the web root, not
+      // the JSON API — see api.webRoot().
+      const base = api.webRoot();
       const slug = encodeURIComponent(msg.slug || '');
       if (!base || !slug) return { error: 'apiUrl or slug missing' };
       try {
diff --git a/extension/lib/api.js b/extension/lib/api.js
index 2554a97..a6b71b2 100644
--- a/extension/lib/api.js
+++ b/extension/lib/api.js
@@ -96,6 +96,13 @@ class FabledCuratorAPI {
     return this.request('GET', '/extension/manifest');
   }
 
+  // The web/SPA root: baseUrl with the trailing slash + `/api` suffix stripped.
+  // Where the Vue router (artist pages) and the served XPI live, NOT the JSON
+  // API. Used by OPEN_ARTIST_PAGE + the self-update check.
+  webRoot() {
+    return (this.baseUrl || '').replace(/\/+$/, '').replace(/\/api$/, '');
+  }
+
   // Connection test = the cheapest read with auth.
   testConnection() {
     return this.request('GET', '/credentials');
diff --git a/extension/popup/popup.js b/extension/popup/popup.js
index 8983d8b..4ffcd8e 100644
--- a/extension/popup/popup.js
+++ b/extension/popup/popup.js
@@ -2,6 +2,15 @@ document.addEventListener('DOMContentLoaded', init);
 
 const CONNECTION_TEST_INTERVAL = 2 * 60 * 1000;
 
+// A centered muted note div — the loading / empty state shared by the platform
+// and sources lists.
+function mutedNote(text) {
+  const d = document.createElement('div');
+  d.style.cssText = 'text-align:center;padding:18px;color:var(--on-surface-variant);';
+  d.textContent = text;
+  return d;
+}
+
 async function init() {
   try {
     const cfg = await browser.runtime.sendMessage({ type: 'GET_CONFIG' });
@@ -38,10 +47,7 @@ function showSetupRequired() {
 function showPlatformsLoading() {
   const c = document.getElementById('platforms-list');
   c.textContent = '';
-  const d = document.createElement('div');
-  d.style.cssText = 'text-align:center;padding:18px;color:var(--on-surface-variant);';
-  d.textContent = 'Loading platforms…';
-  c.appendChild(d);
+  c.appendChild(mutedNote('Loading platforms…'));
 }
 
 async function testConnectionIfNeeded() {
@@ -183,10 +189,7 @@ async function exportAllCookies() {
 async function loadSources() {
   const c = document.getElementById('sources-list');
   c.textContent = '';
-  const d = document.createElement('div');
-  d.style.cssText = 'text-align:center;padding:18px;color:var(--on-surface-variant);';
-  d.textContent = 'Loading sources…';
-  c.appendChild(d);
+  c.appendChild(mutedNote('Loading sources…'));
   const r = await browser.runtime.sendMessage({ type: 'LIST_SOURCES' });
   c.textContent = '';
   if (r.error) {
@@ -197,10 +200,7 @@ async function loadSources() {
     return;
   }
   if (!r.sources || r.sources.length === 0) {
-    const empty = document.createElement('div');
-    empty.style.cssText = 'text-align:center;padding:18px;color:var(--on-surface-variant);';
-    empty.textContent = 'No sources yet.';
-    c.appendChild(empty);
+    c.appendChild(mutedNote('No sources yet.'));
     return;
   }
   for (const src of r.sources) c.appendChild(createSourceRow(src));
diff --git a/frontend/src/components/common/SettingNumberField.vue b/frontend/src/components/common/SettingNumberField.vue
new file mode 100644
index 0000000..3575f33
--- /dev/null
+++ b/frontend/src/components/common/SettingNumberField.vue
@@ -0,0 +1,56 @@
+<!--
+  Canonical settings number field (DRY pass #161): a compact numeric v-text-field
+  with a built-in clamp to [min,max] on commit. Hand-rolled identically across the
+  ML settings cards (HeadsCard x6, CropProposersCard, VideoEmbeddingCard).
+
+  The clamp is the point: the cards previously sent Number(raw) straight to the
+  API, so an out-of-range value bounced off the API's 400 validator (only
+  TranslationCard clamped). This is now the single home for that clamp.
+
+  Binds `modelValue` (v-model) and emits `change` on blur/enter AFTER clamping, so
+  the parent's save reads the already-clamped value — same as the prior
+  `v-model.number` + `@change=save` pattern.
+-->
+<template>
+  <v-text-field
+    :model-value="modelValue"
+    :label="label"
+    type="number"
+    :min="min"
+    :max="max"
+    :step="step"
+    :disabled="disabled"
+    :density="density" hide-details
+    :style="{ maxWidth }"
+    @update:model-value="v => emit('update:modelValue', v)"
+    @change="onCommit"
+  />
+</template>
+
+<script setup>
+const props = defineProps({
+  modelValue: { type: [Number, String], default: null },
+  label: { type: String, default: '' },
+  min: { type: [Number, String], default: null },
+  max: { type: [Number, String], default: null },
+  step: { type: [Number, String], default: 1 },
+  maxWidth: { type: String, default: '200px' },
+  density: { type: String, default: 'compact' },
+  disabled: { type: Boolean, default: false },
+})
+const emit = defineEmits(['update:modelValue', 'change'])
+
+function onCommit() {
+  // On blur/enter: coerce to a number and clamp to [min,max] so an out-of-range
+  // value never reaches the API. props.modelValue reflects the latest keystroke
+  // (kept in sync by the passthrough above); re-emit the clamped number, then let
+  // the parent persist.
+  let n = Number(props.modelValue)
+  if (!Number.isNaN(n)) {
+    if (props.min !== null && props.min !== '') n = Math.max(Number(props.min), n)
+    if (props.max !== null && props.max !== '') n = Math.min(Number(props.max), n)
+    if (n !== Number(props.modelValue)) emit('update:modelValue', n)
+  }
+  emit('change')
+}
+</script>
diff --git a/frontend/src/components/common/SettingToggleRow.vue b/frontend/src/components/common/SettingToggleRow.vue
new file mode 100644
index 0000000..44c147b
--- /dev/null
+++ b/frontend/src/components/common/SettingToggleRow.vue
@@ -0,0 +1,42 @@
+<!--
+  Canonical settings toggle row (DRY pass #161): an accent icon + an uppercase
+  .fc-section-h label + a right-aligned switch. Hand-rolled identically in the
+  ML settings cards (HeadsCard x3, CropProposersCard, MLBackfillCard).
+
+  Two-way binds `modelValue` (so the parent switch state stays optimistic) AND
+  emits `change` with the new boolean, so the parent can persist + revert on
+  failure — matching the prior `v-model` + `@update:model-value=handler` pattern.
+-->
+<template>
+  <div class="d-flex align-center mb-1" style="gap: 10px;">
+    <v-icon v-if="icon" size="18" :color="iconColor">{{ icon }}</v-icon>
+    <span class="fc-section-h">{{ label }}</span>
+    <v-switch
+      :model-value="modelValue"
+      :loading="loading"
+      :disabled="disabled"
+      hide-details density="compact" color="success" class="ml-auto"
+      @update:model-value="onSwitch"
+    />
+  </div>
+</template>
+
+<script setup>
+defineProps({
+  modelValue: { type: Boolean, default: false },
+  label: { type: String, default: '' },
+  icon: { type: String, default: '' },
+  // Icon tint. Default accent; pass null for the theme default (e.g. when a row
+  // is off). null (not undefined) so the default doesn't override it.
+  iconColor: { type: String, default: 'accent' },
+  loading: { type: Boolean, default: false },
+  disabled: { type: Boolean, default: false },
+})
+const emit = defineEmits(['update:modelValue', 'change'])
+
+function onSwitch(v) {
+  const b = !!v
+  emit('update:modelValue', b)
+  emit('change', b)
+}
+</script>
diff --git a/frontend/src/components/settings/CropProposersCard.vue b/frontend/src/components/settings/CropProposersCard.vue
index 46edd54..fb0ca81 100644
--- a/frontend/src/components/settings/CropProposersCard.vue
+++ b/frontend/src/components/settings/CropProposersCard.vue
@@ -15,28 +15,23 @@
     </p>
 
     <div v-for="p in proposers" :key="p.key" class="fc-proposer">
-      <div class="d-flex align-center mb-1" style="gap: 10px;">
-        <v-icon size="18" :color="p.on ? 'accent' : undefined">{{ p.icon }}</v-icon>
-        <span class="fc-section-h">{{ p.label }}</span>
-        <v-switch
-          v-model="p.on" :loading="busy" hide-details density="compact"
-          color="success" class="ml-auto"
-          @update:model-value="v => saveToggle(p, v)"
-        />
-      </div>
+      <SettingToggleRow
+        v-model="p.on" :loading="busy" :icon="p.icon"
+        :icon-color="p.on ? 'accent' : null" :label="p.label"
+        @change="v => saveToggle(p, v)"
+      />
       <p class="fc-muted text-body-2 mb-2">{{ p.help }}</p>
       <div class="d-flex flex-wrap mb-4" style="gap: 12px;">
         <v-text-field
           v-model="p.weights" label="Weights" density="compact" hide-details
           style="min-width: 300px; flex: 1;" :disabled="busy || !p.on"
           placeholder="name | URL | hf_repo::file"
-          @change="save({ [`detector_${p.key}_weights`]: p.weights })"
+          @change="saveField({ [`detector_${p.key}_weights`]: p.weights })"
         />
-        <v-text-field
-          v-model.number="p.conf" label="Confidence" type="number"
-          min="0" max="1" step="0.05" density="compact" hide-details
-          style="max-width: 140px;" :disabled="busy || !p.on"
-          @change="save({ [`detector_${p.key}_conf`]: Number(p.conf) })"
+        <SettingNumberField
+          v-model="p.conf" label="Confidence" :min="0" :max="1" :step="0.05"
+          max-width="140px" :disabled="busy || !p.on"
+          @change="saveField({ [`detector_${p.key}_conf`]: Number(p.conf) })"
         />
       </div>
     </div>
@@ -48,12 +43,12 @@
         storage. Dedupe IoU drops near-duplicate crops before embedding.
       </p>
       <div class="d-flex flex-wrap" style="gap: 12px;">
-        <v-text-field
+        <SettingNumberField
           v-for="c in caps" :key="c.key"
-          v-model.number="c.val" :label="c.label" type="number"
-          :min="c.min" :max="c.max" :step="c.step || 1" density="compact"
-          hide-details style="max-width: 165px;" :disabled="busy"
-          @change="save({ [c.key]: Number(c.val) })"
+          v-model="c.val" :label="c.label"
+          :min="c.min" :max="c.max" :step="c.step || 1"
+          max-width="165px" :disabled="busy"
+          @change="saveField({ [c.key]: Number(c.val) })"
         />
       </div>
     </div>
@@ -61,14 +56,16 @@
 </template>
 
 <script setup>
-import { toast } from '../../utils/toast.js'
 import { onMounted, ref } from 'vue'
 
 import MaintenanceTile from '../common/MaintenanceTile.vue'
+import SettingNumberField from '../common/SettingNumberField.vue'
+import SettingToggleRow from '../common/SettingToggleRow.vue'
+import { useSettingSave } from '../../composables/useSettingSave.js'
 import { useMLStore } from '../../stores/ml.js'
 
 const mlSettings = useMLStore()
-const busy = ref(false)
+const { busy, save } = useSettingSave(mlSettings.patchSettings)
 const proposers = ref([])
 const caps = ref([])
 
@@ -111,31 +108,20 @@ onMounted(async () => {
   caps.value = CAP_DEFS.map(c => ({ ...c, val: s[c.key] ?? 0 }))
 })
 
-async function save(patch, revert) {
-  busy.value = true
-  try {
-    await mlSettings.patchSettings(patch)
-    toast({ text: 'Saved', type: 'success' })
-  } catch (e) {
-    if (revert) revert()
-    toast({ text: `Could not save: ${e.message}`, type: 'error' })
-  } finally {
-    busy.value = false
-  }
+// Field @change → persist with a "Saved" confirmation. SettingNumberField has
+// already clamped numeric values to their [min,max] before this fires.
+function saveField(patch) {
+  save(patch, { successMessage: 'Saved' })
 }
 
-function saveToggle (p, v) {
+async function saveToggle(p, v) {
   // Revert the switch on failure so it never lies about the persisted state.
-  save({ [`detector_${p.key}_enabled`]: !!v }, () => { p.on = !v })
+  const ok = await save({ [`detector_${p.key}_enabled`]: !!v }, { successMessage: 'Saved' })
+  if (!ok) p.on = !v
 }
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
-.fc-section-h {
-  font-size: 13px; font-weight: 700; letter-spacing: 0.03em;
-  text-transform: uppercase; color: rgb(var(--v-theme-on-surface));
-}
 .fc-proposer {
   border-top: 1px solid rgb(var(--v-theme-surface-light)); padding-top: 14px;
 }
diff --git a/frontend/src/components/settings/DangerZoneCard.vue b/frontend/src/components/settings/DangerZoneCard.vue
index a876a7d..ca7adce 100644
--- a/frontend/src/components/settings/DangerZoneCard.vue
+++ b/frontend/src/components/settings/DangerZoneCard.vue
@@ -112,7 +112,6 @@ async function onCommit() {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 .fc-code {
   background: rgb(var(--v-theme-surface-light));
   border-radius: 4px; padding: 2px 8px;
diff --git a/frontend/src/components/settings/DbMaintenanceCard.vue b/frontend/src/components/settings/DbMaintenanceCard.vue
index 18073ba..3e16f13 100644
--- a/frontend/src/components/settings/DbMaintenanceCard.vue
+++ b/frontend/src/components/settings/DbMaintenanceCard.vue
@@ -42,7 +42,7 @@
           </tr>
         </tbody>
       </v-table>
-      <p v-else class="text-caption mt-3" style="opacity: 0.6;">
+      <p v-else class="text-caption mt-3 fc-muted">
         No table statistics yet.
       </p>
   </MaintenanceTile>
diff --git a/frontend/src/components/settings/DownloadsActivityPanel.vue b/frontend/src/components/settings/DownloadsActivityPanel.vue
index a3d379f..d8f9d16 100644
--- a/frontend/src/components/settings/DownloadsActivityPanel.vue
+++ b/frontend/src/components/settings/DownloadsActivityPanel.vue
@@ -72,6 +72,5 @@ onUnmounted(() => { if (pollId) clearInterval(pollId) })
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 .fc-bad { color: rgb(var(--v-theme-error)); }
 </style>
diff --git a/frontend/src/components/settings/GpuActivityPanel.vue b/frontend/src/components/settings/GpuActivityPanel.vue
index 7378309..39bba29 100644
--- a/frontend/src/components/settings/GpuActivityPanel.vue
+++ b/frontend/src/components/settings/GpuActivityPanel.vue
@@ -95,7 +95,6 @@ onUnmounted(() => { if (pollId) clearInterval(pollId) })
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 .fc-cells { display: flex; gap: 28px; }
 .fc-cell__n {
   font-size: 20px; font-weight: 700; line-height: 1.1;
@@ -105,6 +104,5 @@ onUnmounted(() => { if (pollId) clearInterval(pollId) })
   font-size: 11px; text-transform: uppercase; letter-spacing: 0.04em;
   color: rgb(var(--v-theme-on-surface-variant));
 }
-.fc-good { color: rgb(var(--v-theme-success)); }
 .fc-bad { color: rgb(var(--v-theme-error)); }
 </style>
diff --git a/frontend/src/components/settings/GpuAgentCard.vue b/frontend/src/components/settings/GpuAgentCard.vue
index b9a8492..fca73fa 100644
--- a/frontend/src/components/settings/GpuAgentCard.vue
+++ b/frontend/src/components/settings/GpuAgentCard.vue
@@ -367,11 +367,6 @@ async function onReprocess() {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
-.fc-section-h {
-  font-size: 13px; font-weight: 700; letter-spacing: 0.03em;
-  text-transform: uppercase; color: rgb(var(--v-theme-on-surface));
-}
 .fc-token {
   display: flex; align-items: center; gap: 4px;
   background: rgb(var(--v-theme-surface-light)); border-radius: 6px;
@@ -390,6 +385,4 @@ async function onReprocess() {
   font-size: 11px; text-transform: uppercase; letter-spacing: 0.04em;
   color: rgb(var(--v-theme-on-surface-variant));
 }
-.fc-good { color: rgb(var(--v-theme-success)); }
-.fc-weak { color: rgb(var(--v-theme-error)); }
 </style>
diff --git a/frontend/src/components/settings/GpuTriageCard.vue b/frontend/src/components/settings/GpuTriageCard.vue
index a2ab8ac..6f24c38 100644
--- a/frontend/src/components/settings/GpuTriageCard.vue
+++ b/frontend/src/components/settings/GpuTriageCard.vue
@@ -155,11 +155,6 @@ async function onRecover(it) {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
-.fc-section-h {
-  font-size: 13px; font-weight: 700; letter-spacing: 0.03em;
-  text-transform: uppercase; color: rgb(var(--v-theme-on-surface));
-}
 .fc-queue { display: flex; gap: 24px; }
 .fc-q__n {
   font-size: 20px; font-weight: 700; line-height: 1.1;
@@ -169,8 +164,6 @@ async function onRecover(it) {
   font-size: 11px; text-transform: uppercase; letter-spacing: 0.04em;
   color: rgb(var(--v-theme-on-surface-variant));
 }
-.fc-good { color: rgb(var(--v-theme-success)); }
-.fc-weak { color: rgb(var(--v-theme-error)); }
 .fc-defect {
   display: flex; align-items: center; gap: 12px;
   background: rgb(var(--v-theme-surface-light)); border-radius: 8px;
diff --git a/frontend/src/components/settings/HeadsCard.vue b/frontend/src/components/settings/HeadsCard.vue
index 52284f4..4400bcd 100644
--- a/frontend/src/components/settings/HeadsCard.vue
+++ b/frontend/src/components/settings/HeadsCard.vue
@@ -95,14 +95,10 @@
 
     <!-- Earned auto-apply -->
     <div class="fc-auto mt-6">
-      <div class="d-flex align-center mb-1" style="gap: 10px;">
-        <v-icon size="18" color="accent">mdi-lightning-bolt</v-icon>
-        <span class="fc-section-h">Auto-apply</span>
-        <v-switch
-          v-model="autoEnabled" :loading="settingBusy" hide-details density="compact"
-          color="success" class="ml-auto" @update:model-value="onToggleAuto"
-        />
-      </div>
+      <SettingToggleRow
+        v-model="autoEnabled" :loading="settingBusy"
+        icon="mdi-lightning-bolt" label="Auto-apply" @change="onToggleAuto"
+      />
       <p class="fc-muted text-body-2 mb-3">
         Graduated heads (⚡, with ≥ {{ autoMinPosInput }} examples) apply their tag
         on their own where they clear {{ Math.round((autoPrecisionInput || 0) * 100) }}%
@@ -111,17 +107,14 @@
       </p>
 
       <div class="d-flex mb-3" style="gap: 12px;">
-        <v-text-field
-          v-model.number="autoPrecisionInput" label="Precision target"
-          type="number" min="0.5" max="0.999" step="0.01" density="compact"
-          hide-details style="max-width: 200px;" :disabled="settingBusy"
+        <SettingNumberField
+          v-model="autoPrecisionInput" label="Precision target"
+          :min="0.5" :max="0.999" :step="0.01" :disabled="settingBusy"
           @change="onSaveSettings"
         />
-        <v-text-field
-          v-model.number="autoMinPosInput" label="Min examples to fire"
-          type="number" min="1" density="compact" hide-details
-          style="max-width: 200px;" :disabled="settingBusy"
-          @change="onSaveSettings"
+        <SettingNumberField
+          v-model="autoMinPosInput" label="Min examples to fire"
+          :min="1" :disabled="settingBusy" @change="onSaveSettings"
         />
       </div>
 
@@ -161,15 +154,11 @@
 
     <!-- Presentation chrome auto-hide (#141) -->
     <div class="fc-auto mt-6">
-      <div class="d-flex align-center mb-1" style="gap: 10px;">
-        <v-icon size="18" color="accent">mdi-image-off-outline</v-icon>
-        <span class="fc-section-h">Hide presentation chrome</span>
-        <v-switch
-          v-model="presentationEnabled" :loading="settingBusy" hide-details
-          density="compact" color="success" class="ml-auto"
-          @update:model-value="onTogglePresentation"
-        />
-      </div>
+      <SettingToggleRow
+        v-model="presentationEnabled" :loading="settingBusy"
+        icon="mdi-image-off-outline" label="Hide presentation chrome"
+        @change="onTogglePresentation"
+      />
       <p class="fc-muted text-body-2 mb-3">
         Auto-hide <code>banner</code> chrome from the gallery once a head has
         learned it (≥ {{ minPositives }} examples) and clears
@@ -180,16 +169,14 @@
         tag), it's flagged for review instead of buried. Every auto-hide is reversible.
       </p>
       <div class="d-flex mb-3" style="gap: 12px;">
-        <v-text-field
-          v-model.number="presentationThresholdInput" label="Hide confidence"
-          type="number" min="0.5" max="0.999" step="0.01" density="compact"
-          hide-details style="max-width: 200px;" :disabled="settingBusy"
+        <SettingNumberField
+          v-model="presentationThresholdInput" label="Hide confidence"
+          :min="0.5" :max="0.999" :step="0.01" :disabled="settingBusy"
           @change="onSavePresentation"
         />
-        <v-text-field
-          v-model.number="presentationConflictInput" label="Flag if content ≥"
-          type="number" min="0" max="1" step="0.05" density="compact"
-          hide-details style="max-width: 200px;" :disabled="settingBusy"
+        <SettingNumberField
+          v-model="presentationConflictInput" label="Flag if content ≥"
+          :min="0" :max="1" :step="0.05" :disabled="settingBusy"
           @change="onSavePresentation"
         />
       </div>
@@ -197,15 +184,11 @@
 
     <!-- Process auto-tagging (#1464): wip / editor screenshot -->
     <div class="fc-auto mt-6">
-      <div class="d-flex align-center mb-1" style="gap: 10px;">
-        <v-icon size="18" color="accent">mdi-progress-wrench</v-icon>
-        <span class="fc-section-h">Auto-tag work-in-progress</span>
-        <v-switch
-          v-model="processEnabled" :loading="settingBusy" hide-details
-          density="compact" color="success" class="ml-auto"
-          @update:model-value="onToggleProcess"
-        />
-      </div>
+      <SettingToggleRow
+        v-model="processEnabled" :loading="settingBusy"
+        icon="mdi-progress-wrench" label="Auto-tag work-in-progress"
+        @change="onToggleProcess"
+      />
       <p class="fc-muted text-body-2 mb-3">
         Auto-tag <code>wip</code> and <code>editor screenshot</code> process art
         once a head has learned them (≥ {{ minPositives }} examples) and clears
@@ -217,16 +200,14 @@
         manual tags, never its own guesses — so it can't run away. Every tag reversible.
       </p>
       <div class="d-flex mb-3" style="gap: 12px;">
-        <v-text-field
-          v-model.number="processThresholdInput" label="Tag confidence"
-          type="number" min="0.5" max="0.999" step="0.01" density="compact"
-          hide-details style="max-width: 200px;" :disabled="settingBusy"
+        <SettingNumberField
+          v-model="processThresholdInput" label="Tag confidence"
+          :min="0.5" :max="0.999" :step="0.01" :disabled="settingBusy"
           @change="onSaveProcess"
         />
-        <v-text-field
-          v-model.number="processConflictInput" label="Flag if content ≥"
-          type="number" min="0" max="1" step="0.05" density="compact"
-          hide-details style="max-width: 200px;" :disabled="settingBusy"
+        <SettingNumberField
+          v-model="processConflictInput" label="Flag if content ≥"
+          :min="0" :max="1" :step="0.05" :disabled="settingBusy"
           @change="onSaveProcess"
         />
       </div>
@@ -256,7 +237,7 @@
               <td class="fc-r fc-mono">{{ c.n_auto_applied }}</td>
               <td class="fc-r fc-mono">{{ c.n_misfires }}</td>
               <td class="fc-r fc-mono" :class="rateClass(c.misfire_rate)">
-                {{ ratePct(c.misfire_rate) }}
+                {{ pct(c.misfire_rate) }}
               </td>
               <td class="fc-r fc-mono">{{ c.n_underfires }}</td>
             </tr>
@@ -272,6 +253,9 @@ import { toast } from '../../utils/toast.js'
 import { computed, onMounted, onUnmounted, ref } from 'vue'
 
 import MaintenanceTile from '../common/MaintenanceTile.vue'
+import SettingNumberField from '../common/SettingNumberField.vue'
+import SettingToggleRow from '../common/SettingToggleRow.vue'
+import { useSettingSave } from '../../composables/useSettingSave.js'
 import { useHeadsStore } from '../../stores/heads.js'
 import { useMLStore } from '../../stores/ml.js'
 
@@ -285,7 +269,9 @@ let pollTimer = null
 const autoEnabled = ref(false)
 const autoPrecisionInput = ref(0.97)
 const autoMinPosInput = ref(30)
-const settingBusy = ref(false)
+// Shared settings-save flow (busy + toast + revert); `settingBusy` gates the
+// toggles/fields, `save` returns ok/false for the optimistic-switch revert.
+const { busy: settingBusy, save } = useSettingSave(mlSettings.patchSettings)
 const autoBusy = ref(false)
 const autoStatus = ref(null)
 const metricsData = ref(null)
@@ -395,81 +381,39 @@ function startAutoPoll() {
 function stopAutoPoll() { if (autoTimer) { clearInterval(autoTimer); autoTimer = null } }
 
 async function onToggleAuto(val) {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({ head_auto_apply_enabled: !!val })
-    toast({ text: val ? 'Auto-apply on' : 'Auto-apply off', type: 'success' })
-  } catch (e) {
-    autoEnabled.value = !val   // revert the switch
-    toast({ text: `Could not update: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  const ok = await save({ head_auto_apply_enabled: !!val },
+    { successMessage: val ? 'Auto-apply on' : 'Auto-apply off', errorPrefix: 'Could not update' })
+  if (!ok) autoEnabled.value = !val   // revert the switch
 }
 async function onSaveSettings() {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({
-      head_auto_apply_precision: Number(autoPrecisionInput.value),
-      head_auto_apply_min_positives: Number(autoMinPosInput.value),
-    })
-  } catch (e) {
-    toast({ text: `Could not save: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  await save({
+    head_auto_apply_precision: Number(autoPrecisionInput.value),
+    head_auto_apply_min_positives: Number(autoMinPosInput.value),
+  })
 }
 
 async function onTogglePresentation(val) {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({ presentation_auto_apply_enabled: !!val })
-    toast({ text: val ? 'Chrome auto-hide on' : 'Chrome auto-hide off', type: 'success' })
-  } catch (e) {
-    presentationEnabled.value = !val   // revert the switch
-    toast({ text: `Could not update: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  const ok = await save({ presentation_auto_apply_enabled: !!val },
+    { successMessage: val ? 'Chrome auto-hide on' : 'Chrome auto-hide off', errorPrefix: 'Could not update' })
+  if (!ok) presentationEnabled.value = !val   // revert the switch
 }
 async function onSavePresentation() {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({
-      presentation_auto_apply_threshold: Number(presentationThresholdInput.value),
-      presentation_conflict_threshold: Number(presentationConflictInput.value),
-    })
-  } catch (e) {
-    toast({ text: `Could not save: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  await save({
+    presentation_auto_apply_threshold: Number(presentationThresholdInput.value),
+    presentation_conflict_threshold: Number(presentationConflictInput.value),
+  })
 }
 
 async function onToggleProcess(val) {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({ process_auto_apply_enabled: !!val })
-    toast({ text: val ? 'WIP auto-tag on' : 'WIP auto-tag off', type: 'success' })
-  } catch (e) {
-    processEnabled.value = !val   // revert the switch
-    toast({ text: `Could not update: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  const ok = await save({ process_auto_apply_enabled: !!val },
+    { successMessage: val ? 'WIP auto-tag on' : 'WIP auto-tag off', errorPrefix: 'Could not update' })
+  if (!ok) processEnabled.value = !val   // revert the switch
 }
 async function onSaveProcess() {
-  settingBusy.value = true
-  try {
-    await mlSettings.patchSettings({
-      process_auto_apply_threshold: Number(processThresholdInput.value),
-      process_conflict_threshold: Number(processConflictInput.value),
-    })
-  } catch (e) {
-    toast({ text: `Could not save: ${e.message}`, type: 'error' })
-  } finally {
-    settingBusy.value = false
-  }
+  await save({
+    process_auto_apply_threshold: Number(processThresholdInput.value),
+    process_conflict_threshold: Number(processConflictInput.value),
+  })
 }
 function onPreview() { startSweep(true) }
 function onApplyNow() { startSweep(false) }
@@ -495,7 +439,6 @@ function sweepConcepts(run) {
     .sort((a, b) => b.applied - a.applied)
 }
 function sweepTotal(run) { return run?.n_applied ?? 0 }
-function ratePct(x) { return x == null ? '—' : `${Math.round(x * 100)}%` }
 function rateClass(x) {
   if (x == null) return ''
   if (x <= 0.03) return 'fc-good'
@@ -526,12 +469,6 @@ function relTime(iso) {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
-
-.fc-section-h {
-  font-size: 13px; font-weight: 700; letter-spacing: 0.03em;
-  text-transform: uppercase; color: rgb(var(--v-theme-on-surface));
-}
 .fc-auto {
   border-top: 1px solid rgb(var(--v-theme-surface-light)); padding-top: 16px;
 }
@@ -588,7 +525,5 @@ function relTime(iso) {
   background: rgb(var(--v-theme-surface-light));
   padding: 1px 6px; border-radius: 999px;
 }
-.fc-good { color: rgb(var(--v-theme-success)); }
 .fc-ok { color: rgb(var(--v-theme-on-surface)); }
-.fc-weak { color: rgb(var(--v-theme-error)); }
 </style>
diff --git a/frontend/src/components/settings/MLBackfillCard.vue b/frontend/src/components/settings/MLBackfillCard.vue
index 3becc59..dafae6f 100644
--- a/frontend/src/components/settings/MLBackfillCard.vue
+++ b/frontend/src/components/settings/MLBackfillCard.vue
@@ -39,13 +39,14 @@
 import { toast } from '../../utils/toast.js'
 import { onMounted, ref } from 'vue'
 import { useMLStore } from '../../stores/ml.js'
+import { useSettingSave } from '../../composables/useSettingSave.js'
 import MaintenanceTile from '../common/MaintenanceTile.vue'
 import QueueStatusBar from './QueueStatusBar.vue'
 const store = useMLStore()
+const { busy: saving, save } = useSettingSave(store.patchSettings)
 const busy = ref(false)
 const done = ref(false)
 const enabled = ref(true)
-const saving = ref(false)
 onMounted(async () => {
   try {
     await store.loadSettings()
@@ -55,21 +56,12 @@ onMounted(async () => {
   } catch { /* non-fatal */ }
 })
 async function onToggle() {
-  saving.value = true
-  try {
-    await store.patchSettings({ cpu_embed_enabled: enabled.value })
-    toast({
-      text: enabled.value
-        ? 'CPU embedding on — imports queue embeds for the ml-worker'
-        : 'CPU embedding off — the GPU embed backfill owns whole-image embeds',
-      type: 'success',
-    })
-  } catch (e) {
-    toast({ text: `Could not save: ${e.message}`, type: 'error' })
-    enabled.value = !enabled.value
-  } finally {
-    saving.value = false
-  }
+  const ok = await save({ cpu_embed_enabled: enabled.value }, {
+    successMessage: enabled.value
+      ? 'CPU embedding on — imports queue embeds for the ml-worker'
+      : 'CPU embedding off — the GPU embed backfill owns whole-image embeds',
+  })
+  if (!ok) enabled.value = !enabled.value
 }
 async function run() {
   busy.value = true
@@ -80,5 +72,4 @@ async function run() {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 </style>
diff --git a/frontend/src/components/settings/MaintenancePanel.vue b/frontend/src/components/settings/MaintenancePanel.vue
index b379015..372f920 100644
--- a/frontend/src/components/settings/MaintenancePanel.vue
+++ b/frontend/src/components/settings/MaintenancePanel.vue
@@ -24,6 +24,7 @@
         the CPU fallback.
       </p>
       <div class="fc-tile-stack">
+        <VideoEmbeddingCard />
         <GpuAgentCard />
         <GpuTriageCard />
         <MLBackfillCard />
@@ -36,7 +37,6 @@
         Suggestion thresholds, trained heads and tag aliases.
       </p>
       <div class="fc-tile-stack">
-        <MLThresholdSliders />
         <CropProposersCard />
         <HeadsCard />
         <AliasTable />
@@ -77,7 +77,7 @@ import ArchiveReextractCard from './ArchiveReextractCard.vue'
 import MissingFileRepairCard from './MissingFileRepairCard.vue'
 import GpuTriageCard from './GpuTriageCard.vue'
 import DbMaintenanceCard from './DbMaintenanceCard.vue'
-import MLThresholdSliders from './MLThresholdSliders.vue'
+import VideoEmbeddingCard from './VideoEmbeddingCard.vue'
 import CropProposersCard from './CropProposersCard.vue'
 import HeadsCard from './HeadsCard.vue'
 import GpuAgentCard from './GpuAgentCard.vue'
diff --git a/frontend/src/components/settings/MLThresholdSliders.vue b/frontend/src/components/settings/VideoEmbeddingCard.vue
similarity index 53%
rename from frontend/src/components/settings/MLThresholdSliders.vue
rename to frontend/src/components/settings/VideoEmbeddingCard.vue
index 49c4a59..dcd34a9 100644
--- a/frontend/src/components/settings/MLThresholdSliders.vue
+++ b/frontend/src/components/settings/VideoEmbeddingCard.vue
@@ -12,17 +12,17 @@
       </div>
       <v-row>
         <v-col cols="12" sm="6">
-          <v-text-field
-            v-model.number="local.video_frame_interval_seconds"
-            label="Frame interval (s)" type="number" min="0.5" step="0.5"
-            density="comfortable" hide-details @change="save"
+          <SettingNumberField
+            v-model="local.video_frame_interval_seconds"
+            label="Frame interval (s)" :min="0.5" :step="0.5"
+            density="comfortable" max-width="none" @change="onSave"
           />
         </v-col>
         <v-col cols="12" sm="6">
-          <v-text-field
-            v-model.number="local.video_max_frames"
-            label="Max frames" type="number" min="1" step="1"
-            density="comfortable" hide-details @change="save"
+          <SettingNumberField
+            v-model="local.video_max_frames"
+            label="Max frames" :min="1" :step="1"
+            density="comfortable" max-width="none" @change="onSave"
           />
         </v-col>
       </v-row>
@@ -32,21 +32,23 @@
 </template>
 
 <script setup>
-import { toast } from '../../utils/toast.js'
 import { reactive, watch } from 'vue'
 import { useMLStore } from '../../stores/ml.js'
 import MaintenanceTile from '../common/MaintenanceTile.vue'
+import SettingNumberField from '../common/SettingNumberField.vue'
+import { useSettingSave } from '../../composables/useSettingSave.js'
 
 const store = useMLStore()
+const { save } = useSettingSave(store.patchSettings)
 const local = reactive({})
 watch(() => store.settings, (s) => { if (s) Object.assign(local, s) }, { immediate: true })
 
-async function save() {
-  const patch = {
-    video_frame_interval_seconds: local.video_frame_interval_seconds,
-    video_max_frames: local.video_max_frames
-  }
-  try { await store.patchSettings(patch) }
-  catch (e) { toast({ text: e.message, type: 'error' }) }
+// SettingNumberField clamps interval to ≥0.5 and max-frames to ≥1 before this
+// fires, so an out-of-range value never reaches the API.
+function onSave() {
+  save({
+    video_frame_interval_seconds: Number(local.video_frame_interval_seconds),
+    video_max_frames: Number(local.video_max_frames),
+  })
 }
 </script>
diff --git a/frontend/src/composables/useSettingSave.js b/frontend/src/composables/useSettingSave.js
new file mode 100644
index 0000000..dced75d
--- /dev/null
+++ b/frontend/src/composables/useSettingSave.js
@@ -0,0 +1,33 @@
+import { ref } from 'vue'
+import { toast } from '../utils/toast.js'
+
+// The shared "persist a settings patch" flow for the ML settings cards. Flips a
+// busy flag, calls the store's patch (which rethrows on failure), toasts
+// success/error, and returns true/false so a toggle handler can revert its
+// optimistic switch on failure. Centralises the try/catch/toast the cards each
+// hand-rolled (HeadsCard x6, CropProposersCard, MLBackfillCard) — and where the
+// threshold-clamp drifted; the clamp now lives in <SettingNumberField>.
+//
+// Pass the store's patch fn, e.g. useSettingSave(ml.patchSettings).
+export function useSettingSave(patchFn) {
+  const busy = ref(false)
+
+  // opts.successMessage — toast on success (toggles announce their new state;
+  // silent field-saves omit it). opts.errorPrefix — the failure toast prefix
+  // ("Could not save" default; toggles used "Could not update").
+  async function save(patch, { successMessage = '', errorPrefix = 'Could not save' } = {}) {
+    busy.value = true
+    try {
+      await patchFn(patch)
+      if (successMessage) toast({ text: successMessage, type: 'success' })
+      return true
+    } catch (e) {
+      toast({ text: `${errorPrefix}: ${e.message}`, type: 'error' })
+      return false
+    } finally {
+      busy.value = false
+    }
+  }
+
+  return { busy, save }
+}
diff --git a/frontend/src/styles/app.css b/frontend/src/styles/app.css
index e9f9552..3e24a75 100644
--- a/frontend/src/styles/app.css
+++ b/frontend/src/styles/app.css
@@ -40,6 +40,20 @@
    emits, so no specificity/reorder fight — no !important needed. */
 .fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 
+/* Section sub-heading in settings cards (DRY pass #161): was redefined
+   identically in 4 cards, and TranslationCard used the class with NO local def
+   so its section headers rendered unstyled. Now one global utility. */
+.fc-section-h {
+  font-size: 13px; font-weight: 700; letter-spacing: 0.03em;
+  text-transform: uppercase; color: rgb(var(--v-theme-on-surface));
+}
+
+/* Status text colours (DRY pass #161): fc-good = success, fc-weak = error,
+   consolidated from the GPU / heads cards. fc-ok is intentionally NOT global —
+   it means on-surface in HeadsCard but success in QueuesTable. */
+.fc-good { color: rgb(var(--v-theme-success)); }
+.fc-weak { color: rgb(var(--v-theme-error)); }
+
 /* Vuetify 4 dropped its global CSS reset (normalisation moved into each
    component). FC's layouts assumed the reset zeroed margins on text elements, so
    restore just that — the "minimal reset" from the v4 upgrade guide — inside
diff --git a/frontend/src/views/ExploreView.vue b/frontend/src/views/ExploreView.vue
index e352b99..611c95d 100644
--- a/frontend/src/views/ExploreView.vue
+++ b/frontend/src/views/ExploreView.vue
@@ -284,7 +284,6 @@ onUnmounted(() => {
 </script>
 
 <style scoped>
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 
 /* Full-height workspace under the sticky top nav. --fc-nav-h is the nav's REAL
    measured height (set by TopNav) — a hardcoded 64px here overflowed the
diff --git a/frontend/src/views/TagsView.vue b/frontend/src/views/TagsView.vue
index 387d9dc..fbb1bfc 100644
--- a/frontend/src/views/TagsView.vue
+++ b/frontend/src/views/TagsView.vue
@@ -349,7 +349,6 @@ async function onDeleteTagConfirm() {
 .fc-tags__sentinel {
   display: flex; justify-content: center; padding: 32px 0; min-height: 60px;
 }
-.fc-muted { color: rgb(var(--v-theme-on-surface-variant)); }
 .fc-merge-preview {
   padding: 10px 12px;
   border: 1px solid rgba(var(--v-theme-on-surface), 0.12);
diff --git a/tests/test_ml_dry_helpers.py b/tests/test_ml_dry_helpers.py
new file mode 100644
index 0000000..bff8d27
--- /dev/null
+++ b/tests/test_ml_dry_helpers.py
@@ -0,0 +1,59 @@
+"""Shared ML helpers extracted in the DRY pass (milestone #161). These pin the
+single sources the auto-apply sweeps now trust, so a future edit can't silently
+drift them: `_applied_or_rejected` is the skip-set used by auto_apply_sweep,
+system_tag_auto_apply_sweep (heads.py) and scheduled_ccip_auto_apply (tasks/ml.py);
+`_sigmoid` is the head score→prob transform used at every scoring site."""
+import pytest
+
+from backend.app.models import ImageRecord, Tag, TagKind, TagSuggestionRejection
+from backend.app.models.tag import image_tag
+from backend.app.services.ml.training_data import _applied_or_rejected
+
+
+def test_sigmoid_matches_naive_form():
+    import numpy as np
+
+    from backend.app.services.ml.heads import _sigmoid
+
+    z = np.array([-3.0, -0.5, 0.0, 1.5, 12.0], dtype=np.float32)
+    assert np.allclose(_sigmoid(z, np), 1.0 / (1.0 + np.exp(-z)))
+    assert float(_sigmoid(np.array([0.0]), np)[0]) == pytest.approx(0.5)
+
+
+@pytest.mark.integration
+def test_applied_or_rejected_unions_applied_any_source_and_rejected(db_sync):
+    a = Tag(name="dry-helper-a", kind=TagKind.general)
+    b = Tag(name="dry-helper-b", kind=TagKind.general)
+    db_sync.add_all([a, b])
+    db_sync.flush()
+
+    imgs = []
+    for i in range(5):
+        img = ImageRecord(
+            path=f"/images/dryhelp{i}.jpg", sha256=f"{i:064d}", size_bytes=1,
+            mime="image/jpeg", width=1, height=1, origin="imported_filesystem",
+            integrity_status="unknown", siglip_embedding=[0.0] * 1152,
+        )
+        db_sync.add(img)
+        imgs.append(img)
+    db_sync.flush()
+
+    # tag a: applied manually (img0), applied by an AUTO source (img1), rejected (img2).
+    db_sync.execute(image_tag.insert().values(
+        image_record_id=imgs[0].id, tag_id=a.id, source="manual"))
+    db_sync.execute(image_tag.insert().values(
+        image_record_id=imgs[1].id, tag_id=a.id, source="head_auto"))
+    db_sync.add(TagSuggestionRejection(image_record_id=imgs[2].id, tag_id=a.id))
+    # tag b: applied to img3 only.
+    db_sync.execute(image_tag.insert().values(
+        image_record_id=imgs[3].id, tag_id=b.id, source="manual"))
+    db_sync.flush()
+
+    skip = _applied_or_rejected(db_sync, [a.id, b.id])
+
+    # Applied-under-ANY-source (manual + head_auto) ∪ rejected, kept per-tag; the
+    # untouched image (img4) appears under neither tag.
+    assert skip[a.id] == {imgs[0].id, imgs[1].id, imgs[2].id}
+    assert skip[b.id] == {imgs[3].id}
+    assert imgs[4].id not in skip[a.id]
+    assert imgs[4].id not in skip[b.id]
diff --git a/tests/test_recover_stalled_head_runs.py b/tests/test_recover_stalled_head_runs.py
new file mode 100644
index 0000000..778e491
--- /dev/null
+++ b/tests/test_recover_stalled_head_runs.py
@@ -0,0 +1,63 @@
+"""recover_stalled_head_training_runs + recover_stalled_head_auto_apply_runs share
+one helper (_recover_stalled_runs, DRY pass #161). These pin BOTH wrappers so the
+shared source stays correct: a 'running' row with no progress past the stall
+threshold flips to 'error'; a fresh 'running' row is left alone."""
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from sqlalchemy import select
+
+from backend.app.models import HeadAutoApplyRun, HeadTrainingRun
+
+pytestmark = pytest.mark.integration
+
+
+def test_recover_stalled_head_training_runs_flips_stalled_keeps_fresh(db_sync):
+    from backend.app.tasks.maintenance import recover_stalled_head_training_runs
+
+    stale = HeadTrainingRun(
+        params={}, status="running",
+        last_progress_at=datetime.now(UTC) - timedelta(days=1),
+    )
+    fresh = HeadTrainingRun(
+        params={}, status="running", last_progress_at=datetime.now(UTC),
+    )
+    db_sync.add_all([stale, fresh])
+    db_sync.commit()
+    stale_id, fresh_id = stale.id, fresh.id
+
+    assert recover_stalled_head_training_runs.apply().get() == 1
+
+    db_sync.expire_all()
+    assert db_sync.execute(
+        select(HeadTrainingRun.status).where(HeadTrainingRun.id == stale_id)
+    ).scalar_one() == "error"
+    assert db_sync.execute(
+        select(HeadTrainingRun.status).where(HeadTrainingRun.id == fresh_id)
+    ).scalar_one() == "running"
+
+
+def test_recover_stalled_head_auto_apply_runs_flips_stalled_keeps_fresh(db_sync):
+    from backend.app.tasks.maintenance import recover_stalled_head_auto_apply_runs
+
+    stale = HeadAutoApplyRun(
+        dry_run=False, params={}, status="running",
+        last_progress_at=datetime.now(UTC) - timedelta(days=1),
+    )
+    fresh = HeadAutoApplyRun(
+        dry_run=False, params={}, status="running",
+        last_progress_at=datetime.now(UTC),
+    )
+    db_sync.add_all([stale, fresh])
+    db_sync.commit()
+    stale_id, fresh_id = stale.id, fresh.id
+
+    assert recover_stalled_head_auto_apply_runs.apply().get() == 1
+
+    db_sync.expire_all()
+    assert db_sync.execute(
+        select(HeadAutoApplyRun.status).where(HeadAutoApplyRun.id == stale_id)
+    ).scalar_one() == "error"
+    assert db_sync.execute(
+        select(HeadAutoApplyRun.status).where(HeadAutoApplyRun.id == fresh_id)
+    ).scalar_one() == "running"