Add app auth, dashboard, scheduler, video management, and new scrapers

- JWT-based app authentication with user roles, folder/route access control
- Dashboard with storage stats, health checks, and recent activity
- Auto-download/scrape scheduler (12h interval) with per-user and per-job configs
- Video upload, tagging, HLS transcoding, and detail pages
- New scrapers: LeakGallery, Mega (megajs), yt-dlp
- FlareSolverr integration for Cloudflare-protected sites
- Gallery: advanced filtering (date, size, search), sort modes, equal-mix shuffle
- Forum sites management with stored cookies/auth
- GridWall/GridCell components for responsive media grid
- Media API with folder-access permissions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/proxy.js

@@ -55,6 +55,23 @@ async function proxyGet(ofPath, authConfig) {
   return { status: res.status, data };
 }
 
+// GET /api/auth/check — validate auth by calling OF API
+router.get('/api/auth/check', async (req, res) => {
+  try {
+    const authConfig = getAuthConfig();
+    if (!authConfig) {
+      return res.json({ valid: false, error: 'No auth configured' });
+    }
+    const { status, data } = await proxyGet('/api2/v2/users/me', authConfig);
+    if (status === 200 && data && data.id) {
+      return res.json({ valid: true, user: { id: data.id, name: data.name, username: data.username } });
+    }
+    return res.json({ valid: false, error: data?.error?.message || data?.message || `HTTP ${status}` });
+  } catch (err) {
+    return res.json({ valid: false, error: err.message });
+  }
+});
+
 // GET /api/auth
 router.get('/api/auth', (req, res) => {
   const config = getAuthConfig();