feat: profile page, admin pages, infinite scroll on browse

- Add /profile page with reading settings (voice, speed, auto-next) and password change form
- Add /admin/scrape page showing scraping task history with live status polling and trigger controls
- Add /admin/audio page showing audio cache entries with client-side search filter
- Add changePassword(), listAudioCache(), listScrapingTasks() to pocketbase.ts
- Add /api/admin/scrape and /api/browse-page server-side proxy routes
- Replace browse page pagination with IntersectionObserver infinite scroll
- Update nav: username becomes a /profile link; admin users see Scrape and Audio cache links

ui/src/routes/api/admin/scrape/+server.ts

@@ -0,0 +1,23 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { env } from '$env/dynamic/private';
+
+const SCRAPER_URL = env.SCRAPER_API_URL ?? 'http://localhost:8080';
+
+/**
+ * GET /api/admin/scrape/status
+ * Admin-only proxy to the Go scraper's /api/scrape/status endpoint.
+ */
+export const GET: RequestHandler = async ({ locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	try {
+		const res = await fetch(`${SCRAPER_URL}/api/scrape/status`);
+		if (!res.ok) return json({ running: false });
+		const data = await res.json();
+		return json({ running: data.running ?? false });
+	} catch {
+		return json({ running: false });
+	}
+};