fix(analysis): emit Cancelled event + assert lock-release after cancel (0.87.13)

Two 0.87.4 follow-ups:

1. Cron tick: existing shutdown-on-cancel test now also asserts the
   advisory lock is re-acquirable after cancel-during-tick. Without
   this, a refactor moving `pg_advisory_unlock` under the cancel arm
   would ship green and break multi-replica safety.

2. Analysis worker: cancel-mid-dispatch left the dashboard banner stuck
   on the cancelled page until a later page overwrote it. Add a
   `Cancelled` AnalysisEvent variant, publish on the cancel-release
   branch, wire the analysis and admin overview dashboards to clear
   on it. Per-page chip rolls back from `analyzing` to `queued`.

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

frontend/src/lib/api/admin.ts

@@ -857,7 +857,12 @@ export type AnalysisEvent =
           chapter_id: string | null;
       }
     | {
-          kind: 'started' | 'completed' | 'failed';
+          // `cancelled` fires when the worker drops an in-flight dispatch
+          // on daemon shutdown / settings-toggle-off. The lease was
+          // released, not failed — the page returns to pending. The
+          // dashboard banner clears on this so it doesn't stick on the
+          // cancelled page until another `started` overwrites it.
+          kind: 'started' | 'completed' | 'failed' | 'cancelled';
           page_id: string;
           manga_id: string;
           manga_title: string;