feat(agent-office): notification badges + CEO desk document panel + telegram test

- Add notification state management with badge counts in useAgentManager
- Render exclamation badge on agent sprites (separate from status icons)
- Add CEO desk document icon with click-to-open activity panel
- Create DocumentPanel with unified activity feed + per-agent detail tabs
- Add telegram test button to stock agent ChatPanel
- Remove TaskHistory + bottom toolbar (replaced by DocumentPanel)
- Add getActivityFeed API helper

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/pages/agent-office/hooks/useAgentManager.js

@@ -4,6 +4,7 @@ export function useAgentManager() {
   const [agents, setAgents] = useState({});
   const [pendingTasks, setPendingTasks] = useState([]);
   const [connected, setConnected] = useState(false);
+  const [notifications, setNotifications] = useState({});
   const wsRef = useRef(null);
   const reconnectTimer = useRef(null);
 
@@ -58,6 +59,12 @@ export function useAgentManager() {
             [msg.agent]: { ...prev[msg.agent], lastCommand: msg.result },
           }));
           break;
+        case 'notification':
+          setNotifications(prev => ({
+            ...prev,
+            [msg.agent]: (prev[msg.agent] || 0) + 1,
+          }));
+          break;
         default:
           break;
       }
@@ -84,5 +91,13 @@ export function useAgentManager() {
     }
   }, []);
 
-  return { agents, pendingTasks, connected, sendCommand, sendApproval };
+  const clearNotifications = useCallback((agentId) => {
+    setNotifications(prev => {
+      const next = { ...prev };
+      delete next[agentId];
+      return next;
+    });
+  }, []);
+
+  return { agents, pendingTasks, connected, notifications, sendCommand, sendApproval, clearNotifications };
 }