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/lib/server/pocketbase.ts

@@ -479,6 +479,44 @@ export async function createUser(username: string, password: string, role = 'use
 	return res.json() as Promise<User>;
 }
 
+/**
+ * Change a user's password. Verifies the current password first.
+ * Returns true on success, false if currentPassword is wrong.
+ * Throws on unexpected errors.
+ */
+export async function changePassword(
+	userId: string,
+	currentPassword: string,
+	newPassword: string
+): Promise<boolean> {
+	// Fetch the user record directly by id to verify current password
+	const token = await getToken();
+	const res = await fetch(`${PB_URL}/api/collections/app_users/records/${userId}`, {
+		headers: { Authorization: `Bearer ${token}` }
+	});
+	if (!res.ok) {
+		const body = await res.text().catch(() => '');
+		log.error('pocketbase', 'changePassword: fetch user failed', { userId, status: res.status, body });
+		throw new Error(`Failed to fetch user: ${res.status}`);
+	}
+	const user = (await res.json()) as User;
+	if (!verifyPassword(currentPassword, user.password_hash)) {
+		log.warn('pocketbase', 'changePassword: wrong current password', { userId });
+		return false;
+	}
+	const newHash = hashPassword(newPassword);
+	const patch = await pbPatch(`/api/collections/app_users/records/${userId}`, {
+		password_hash: newHash
+	});
+	if (!patch.ok) {
+		const body = await patch.text().catch(() => '');
+		log.error('pocketbase', 'changePassword: PATCH failed', { userId, status: patch.status, body });
+		throw new Error(`Failed to update password: ${patch.status}`);
+	}
+	log.info('pocketbase', 'changePassword: success', { userId });
+	return true;
+}
+
 /**
  * Verify username + password. Returns the user on success, null on failure.
  */
@@ -586,6 +624,39 @@ export async function setAudioTime(
 	}
 }
 
+// ─── Audio cache ──────────────────────────────────────────────────────────────
+
+export interface AudioCacheEntry {
+	id: string;
+	cache_key: string;
+	filename: string;
+	updated: string;
+}
+
+export async function listAudioCache(): Promise<AudioCacheEntry[]> {
+	return listAll<AudioCacheEntry>('audio_cache', '', '-updated');
+}
+
+// ─── Scraping tasks ───────────────────────────────────────────────────────────
+
+export interface ScrapingTask {
+	id: string;
+	kind: string;
+	target_url: string;
+	status: string;
+	books_found: number;
+	chapters_scraped: number;
+	chapters_skipped: number;
+	errors: number;
+	started: string;
+	finished: string;
+	error_message: string;
+}
+
+export async function listScrapingTasks(): Promise<ScrapingTask[]> {
+	return listAll<ScrapingTask>('scraping_tasks', '', '-started');
+}
+
 export async function getAudioTime(
 	sessionId: string,
 	slug: string,