feat(gallery): hidden-view review endpoints — list + keep + un-hide (#141 step 5)

GET /api/gallery/hidden-review lists unresolved presentation auto-hide flags
(image + presentation tag + conflict tag/score), most-concerning first. POST
.../keep resolves the flag (the tag stays). POST .../unhide removes the
presentation tag (image returns to the gallery), records a TagSuggestionRejection
so the head learns it misfired, and resolves the flag. Tests for list/keep/unhide.
Frontend review strip (shown when Show-hidden is on) next.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CDgx8bQS5YrGRK76v8HUnM

backend/app/api/gallery.py

@@ -3,9 +3,18 @@
 from datetime import UTC, datetime, timedelta
 
 from quart import Blueprint, jsonify, request
+from sqlalchemy import delete, select, update
+from sqlalchemy.orm import aliased
 
 from ..extensions import get_session
-from ..services.gallery_service import GalleryService
+from ..models import (
+    ImageRecord,
+    PresentationReview,
+    Tag,
+    TagSuggestionRejection,
+)
+from ..models.tag import image_tag
+from ..services.gallery_service import GalleryService, image_url, thumbnail_url
 
 gallery_bp = Blueprint("gallery", __name__, url_prefix="/api/gallery")
 
@@ -219,6 +228,97 @@ async def jump():
     return jsonify({"cursor": cursor})
 
 
+# -- Hidden-view review (#141): auto-hidden chrome flagged "also looks like
+#    content", surfaced in the gallery's Show-hidden review strip. -----------
+@gallery_bp.route("/hidden-review", methods=["GET"])
+async def hidden_review():
+    """Unresolved presentation auto-hide flags, most-concerning first (highest
+    content score) — for the gallery's Hidden-view review strip."""
+    ptag = aliased(Tag)
+    ctag = aliased(Tag)
+    async with get_session() as session:
+        rows = (await session.execute(
+            select(
+                PresentationReview.image_record_id,
+                PresentationReview.tag_id,
+                PresentationReview.conflict_tag_id,
+                PresentationReview.conflict_score,
+                ImageRecord.path, ImageRecord.thumbnail_path,
+                ImageRecord.sha256, ImageRecord.mime,
+                ptag.name.label("tag_name"),
+                ctag.name.label("conflict_name"),
+            )
+            .join(ImageRecord, ImageRecord.id == PresentationReview.image_record_id)
+            .join(ptag, ptag.id == PresentationReview.tag_id)
+            .outerjoin(ctag, ctag.id == PresentationReview.conflict_tag_id)
+            .where(PresentationReview.resolved_at.is_(None))
+            .order_by(PresentationReview.conflict_score.desc())
+        )).all()
+    return jsonify({"items": [
+        {
+            "image_id": r.image_record_id,
+            "tag_id": r.tag_id,
+            "tag_name": r.tag_name,
+            "conflict_tag_id": r.conflict_tag_id,
+            "conflict_name": r.conflict_name,
+            "conflict_score": r.conflict_score,
+            "thumbnail_url": thumbnail_url(r.thumbnail_path, r.sha256, r.mime),
+            "image_url": image_url(r.path),
+        }
+        for r in rows
+    ]})
+
+
+@gallery_bp.route(
+    "/hidden-review/<int:image_id>/<int:tag_id>/keep", methods=["POST"]
+)
+async def hidden_review_keep(image_id, tag_id):
+    """Keep the auto-hide: resolve the flag; the tag stays applied (#141)."""
+    async with get_session() as session:
+        await session.execute(
+            update(PresentationReview)
+            .where(
+                PresentationReview.image_record_id == image_id,
+                PresentationReview.tag_id == tag_id,
+            )
+            .values(resolved_at=datetime.now(UTC))
+        )
+        await session.commit()
+    return "", 204
+
+
+@gallery_bp.route(
+    "/hidden-review/<int:image_id>/<int:tag_id>/unhide", methods=["POST"]
+)
+async def hidden_review_unhide(image_id, tag_id):
+    """Un-hide: remove the presentation tag (image returns to the gallery), record
+    a rejection so the head LEARNS it misfired, and resolve the flag (#141)."""
+    from sqlalchemy.dialects.postgresql import insert as pg_insert
+
+    async with get_session() as session:
+        await session.execute(
+            delete(image_tag).where(
+                image_tag.c.image_record_id == image_id,
+                image_tag.c.tag_id == tag_id,
+            )
+        )
+        await session.execute(
+            pg_insert(TagSuggestionRejection)
+            .values(image_record_id=image_id, tag_id=tag_id)
+            .on_conflict_do_nothing()
+        )
+        await session.execute(
+            update(PresentationReview)
+            .where(
+                PresentationReview.image_record_id == image_id,
+                PresentationReview.tag_id == tag_id,
+            )
+            .values(resolved_at=datetime.now(UTC))
+        )
+        await session.commit()
+    return "", 204
+
+
 @gallery_bp.route("/image/<int:image_id>", methods=["GET"])
 async def image_detail(image_id: int):
     async with get_session() as session: