feat: add HTTP fallback when WebSocket unavailable

WebSocket connections may not work through Cloudflare Tunnel.
Added HTTP polling fallback that:
- Loads initial data via /api/projects and /api/tasks
- Falls back to 5-second polling if WebSocket fails
- Shows "Polling" status badge when in fallback mode

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/aggregator/web/index.html

@@ -537,19 +537,77 @@
       setTimeout(() => toast.remove(), 3000);
     }
 
+    let usePolling = false;
+    let pollInterval = null;
+
+    // HTTP fallback to load initial data
+    async function loadDataViaHTTP() {
+      try {
+        const [projectsRes, tasksRes] = await Promise.all([
+          fetch('/api/projects'),
+          fetch('/api/tasks')
+        ]);
+        if (projectsRes.ok && tasksRes.ok) {
+          projects = await projectsRes.json();
+          tasks = await tasksRes.json();
+          renderProjects();
+          renderTasks();
+          updateProjectDropdown();
+          return true;
+        }
+      } catch (e) {
+        console.error('HTTP load failed:', e);
+      }
+      return false;
+    }
+
+    // Start polling for updates (fallback when WebSocket unavailable)
+    function startPolling() {
+      if (pollInterval) return;
+      usePolling = true;
+      document.getElementById('status-badge').textContent = 'Polling';
+      pollInterval = setInterval(loadDataViaHTTP, 5000);
+    }
+
     function connectWebSocket() {
       const protocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
       ws = new WebSocket(`${protocol}//${location.host}`);
 
+      // Timeout - if WS doesn't connect in 5s, fall back to HTTP
+      const wsTimeout = setTimeout(async () => {
+        if (ws.readyState !== WebSocket.OPEN) {
+          console.log('WebSocket timeout, falling back to HTTP');
+          ws.close();
+          await loadDataViaHTTP();
+          startPolling();
+        }
+      }, 5000);
+
       ws.onopen = () => {
+        clearTimeout(wsTimeout);
+        usePolling = false;
+        if (pollInterval) {
+          clearInterval(pollInterval);
+          pollInterval = null;
+        }
         document.getElementById('status-badge').textContent = 'Live';
         document.getElementById('status-badge').classList.remove('offline');
       };
 
+      ws.onerror = async () => {
+        clearTimeout(wsTimeout);
+        console.log('WebSocket error, falling back to HTTP');
+        await loadDataViaHTTP();
+        startPolling();
+      };
+
       ws.onclose = () => {
-        document.getElementById('status-badge').textContent = 'Reconnecting...';
+        clearTimeout(wsTimeout);
+        document.getElementById('status-badge').textContent = usePolling ? 'Polling' : 'Reconnecting...';
         document.getElementById('status-badge').classList.add('offline');
+        if (!usePolling) {
           setTimeout(connectWebSocket, 3000);
+        }
       };
 
       ws.onmessage = (event) => {