feat: bulk action progress — header pill + per-thumbnail states

- New bulkAction store: tracks active/label/detail state for the pill
  and a Map<uid, pending|done|error> for per-tile overlays
- Extract StatusPill.svelte from IndexerStatusPill (generic active/label/detail
  props); IndexerStatusPill becomes a one-line wrapper
- +layout.svelte: render a second StatusPill driven by bulkAction store,
  alongside the indexer pill in the AnimatedMule header
- BulkActionBar: extend withBusy with optional BulkConfig (ids/label/doneLabel);
  pending tiles dim + spinner on start, green checkmark flashes for 400ms before
  cache invalidation removes them; red overlay on error, auto-clears after 2s
- onApprove/batchEdit: wire onProgress callback to setDetail so the pill shows
  the filename currently being processed during fan-out keep operations
- batch.ts: add completedId as third arg to onProgress (backwards-compatible)
- PhotoTile: derive bulkState from store; pending/done/error overlays sit above
  the selection tint; hover-video guarded against pending tiles

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/lib/stores/bulkAction.svelte.ts

@@ -0,0 +1,60 @@
+/**
+ * Bulk-action status, written by BulkActionBar and read by the header
+ * StatusPill and individual PhotoTile overlays.
+ *
+ * State lifecycle:
+ *   startBulk  → pill spins, all target tiles go "pending"
+ *   setDetail  → pill shows the filename currently being processed (fan-out ops)
+ *   doneBulk   → pill shows completion label, tiles flash green, auto-clears after 3 s
+ *   failBulk   → tiles flash red, auto-clears after 2 s
+ */
+
+interface BulkActionState {
+	active: boolean;
+	label: string;
+	detail?: string;
+}
+
+export const bulkAction = $state<BulkActionState>({ active: false, label: '' });
+export const bulkPhotoStates = $state(new Map<string, 'pending' | 'done' | 'error'>());
+
+let doneTimer: ReturnType<typeof setTimeout> | null = null;
+
+export function startBulk(label: string, ids: string[]): void {
+	if (doneTimer !== null) {
+		clearTimeout(doneTimer);
+		doneTimer = null;
+	}
+	bulkPhotoStates.clear();
+	for (const id of ids) bulkPhotoStates.set(id, 'pending');
+	bulkAction.active = true;
+	bulkAction.label = label;
+	bulkAction.detail = undefined;
+}
+
+export function setDetail(path: string): void {
+	bulkAction.detail = path;
+}
+
+export function doneBulk(label: string, ids: string[]): void {
+	for (const id of ids) bulkPhotoStates.set(id, 'done');
+	bulkAction.active = false;
+	bulkAction.label = label;
+	bulkAction.detail = undefined;
+	if (doneTimer !== null) clearTimeout(doneTimer);
+	doneTimer = setTimeout(() => {
+		bulkAction.label = '';
+		bulkPhotoStates.clear();
+		doneTimer = null;
+	}, 3000);
+}
+
+export function failBulk(ids: string[]): void {
+	for (const id of ids) bulkPhotoStates.set(id, 'error');
+	bulkAction.active = false;
+	bulkAction.label = '';
+	bulkAction.detail = undefined;
+	setTimeout(() => {
+		for (const id of ids) bulkPhotoStates.delete(id);
+	}, 2000);
+}