Add debug Remove entry, Show more auto-picker, and update docs.

DELETE /api/paintings/:id removes works and image files with gallery refresh and catalog navigation; Show more opens the search modal on load; documentation updated for migrate schema and debug workflow.

Co-authored-by: Cursor <cursoragent@cursor.com>

Documentation/API.md

@@ -542,6 +542,26 @@ Max decoded size 15 MB (JSON body limit 20 MB on the server). **Response** — s
 
 ---
 
+### `DELETE /api/paintings/:id`
+
+Permanently remove a painting (debug **Remove entry** on painting detail). Deletes full + thumbnail files from disk, then deletes the `paintings` row. Related rows in `painting_influence_sources`, `painting_annotations`, and legacy `painting_influences` are removed by `ON DELETE CASCADE`.
+
+**Response**
+
+```json
+{
+  "id": 42,
+  "artistId": 7,
+  "title": "Example Work"
+}
+```
+
+**Errors:** `404` if the painting does not exist.
+
+The client refetches the artist (and movement gallery when applicable), remounts the 3D hall, and opens the next or previous work in the catalog — or returns to the gallery if it was the last work.
+
+---
+
 ### `GET /api/debug/image-proxy`
 
 Proxy a remote image URL for debug preview (avoids hotlink / CORS blocks in the browser).
@@ -576,6 +596,7 @@ The React client wraps these endpoints in `client/src/api/client.ts`:
 | `api.getPaintingDebugImageSearchMore(id, limit?)` | `GET /api/paintings/:id/debug-image-search/more` |
 | `api.fixPaintingImage(id, imageUrl, context?)` | `POST /api/paintings/:id/fix-image` |
 | `api.clearPaintingImage(id)` | `POST /api/paintings/:id/clear-image` |
+| `api.deletePainting(id)` | `DELETE /api/paintings/:id` |
 | `api.uploadPaintingImage(id, file)` | `POST /api/paintings/:id/upload-image` |
 | `api.updateArtistCheckupFlags(id, flags)` | `PATCH /api/artists/:id/checkup-flags` |
 | `api.getArtistDebugPortraitSearch(id)` | `GET /api/artists/:id/debug-portrait-search` |