feat(fc5): /api/migrate/cleanup — delete every image attributed to one artist, files + thumbs + DB

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/tasks/migration.py

@@ -4,7 +4,7 @@ Dispatches to the right migrator based on `kind`. Updates MigrationRun
 row's status/counts/finished_at as it runs. Failures set status='error'
 with the error message preserved.
 
-kinds: backup, gs_ingest, ir_ingest, tag_apply, ml_queue, verify, rollback
+kinds: backup, gs_ingest, ir_ingest, tag_apply, ml_queue, verify, rollback, cleanup
 """
 from __future__ import annotations
 
@@ -21,6 +21,7 @@ from ..config import get_config
 from ..models import MigrationRun
 from ..services.credential_crypto import CredentialCrypto
 from ..services.migrators import backup as backup_mod
+from ..services.migrators import cleanup as cleanup_mod
 from ..services.migrators import gs_ingest, ir_ingest, ml_queue, tag_apply, verify
 from ..services.migrators import rollback as rollback_mod
 
@@ -145,6 +146,26 @@ async def _run_async(run_id: int, kind: str, params: dict) -> dict:
                     )
                     return {"checks": checks, "sample": sample}
 
+                elif kind == "cleanup":
+                    slug = params.get("slug")
+                    if not slug:
+                        raise ValueError("cleanup requires params.slug")
+                    result = await cleanup_mod.cleanup_artist_async(
+                        db, slug=slug, images_root=IMAGES_ROOT,
+                        dry_run=params.get("dry_run", False),
+                        source_path_prefix=params.get("source_path_prefix"),
+                    )
+                    await _update_run(
+                        db, run_id, status="ok",
+                        counts=result["counts"],
+                        finished_at=datetime.now(UTC),
+                        metadata_patch={
+                            "artist": result["artist"],
+                            "summary": result["summary"],
+                        },
+                    )
+                    return result
+
                 elif kind == "rollback":
                     result = rollback_mod.rollback_to_pre_migration(
                         db_url=get_config().database_url_sync,