fix: wire import chapter ingestion, live task polling, a11y labels, notification user targeting

- NewBookImporter now takes *Store instead of raw *minio.Client (same package access)
- Runner Dependencies gains ChapterIngester interface; storeImportedChapters no-op removed
- store.IngestChapters is now actually called after PDF/EPUB extraction
- BookImport and ChapterIngester wired in runner main.go
- CreateImportTask interface gains initiatorUserID param; threaded through store/asynq/handler
- domain.ImportTask gains InitiatorUserID field; parseImportTask populates it
- Runner notifies initiator (falls back to 'admin' when empty)
- UI: import task list polls every 3s while any task is pending/running
- UI: label[for] + input[id] fix for a11y warnings in admin import page

ui/src/routes/api/notifications/+server.ts

@@ -0,0 +1,11 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { backendFetch } from '$lib/server/scraper';
+
+export const GET: RequestHandler = async ({ url }) => {
+	const userId = url.searchParams.get('user_id');
+	if (!userId) throw error(400, 'user_id required');
+	const res = await backendFetch('/api/notifications?user_id=' + userId);
+	const data = await res.json().catch(() => ({ notifications: [] }));
+	return json(data);
+};

ui/src/routes/api/notifications/[id]/+server.ts

@@ -0,0 +1,19 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { backendFetch } from '$lib/server/scraper';
+
+export const GET: RequestHandler = async ({ url }) => {
+	const userId = url.searchParams.get('user_id');
+	if (!userId) throw error(400, 'user_id required');
+	const res = await backendFetch('/api/notifications?user_id=' + userId);
+	const data = await res.json().catch(() => ({ notifications: [] }));
+	return json(data);
+};
+
+export const PATCH: RequestHandler = async ({ params }) => {
+	const id = params.id;
+	if (!id) throw error(400, 'id required');
+	const res = await backendFetch('/api/notifications/' + id, { method: 'PATCH' });
+	const data = await res.json().catch(() => ({}));
+	return json(data);
+};