fix(cleanup): library scans survive navigation, reconnect on return

The transparency / single-color audit cards held the run + poll timer in
local component state, so navigating away destroyed both and onMounted never
reconnected — the Celery scan kept running and writing LibraryAuditRun, but
the UI forgot it. Now each card, on mount, fetches its rule's latest run
(GET /api/cleanup/audit?rule=<rule>&limit=1) and rehydrates: shows progress +
resumes polling if still running, or shows the completed result (ready/applied/
error) so the operator can act on it after returning. Adds the ?rule= filter
to the audit-history endpoint + cleanup store latestAuditForRule().

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/api/cleanup.py

@@ -154,12 +154,15 @@ async def audit_history():
         limit = min(int(request.args.get("limit", "20")), 100)
     except ValueError:
         return _bad("invalid_limit")
+    # Optional rule filter so a card can reconnect to ITS latest run on mount
+    # (?rule=transparency&limit=1) — the audit survives navigation; the UI
+    # rehydrates from this rather than losing the in-flight scan.
+    rule = request.args.get("rule") or None
     async with get_session() as session:
-        rows = (await session.execute(
-            select(LibraryAuditRun)
-            .order_by(LibraryAuditRun.id.desc())
-            .limit(limit)
-        )).scalars().all()
+        stmt = select(LibraryAuditRun).order_by(LibraryAuditRun.id.desc())
+        if rule is not None:
+            stmt = stmt.where(LibraryAuditRun.rule == rule)
+        rows = (await session.execute(stmt.limit(limit))).scalars().all()
         return jsonify({"runs": [_serialize_audit_run(r) for r in rows]})