feat: complete Phase 1 MVP - add agent executor and WebSocket real-time updates

Agent Executor Service:
- BaseAgent class with LLM integration via LiteLLM proxy
- AgentExecutor service that processes pending executions every 5 seconds
- Action execution: create_subtask, update_status, send_notification, add_comment
- Approval workflow: CxO level agents require user approval before execution
- Telegram notifications for approvals and completions
- Error handling and execution status tracking

WebSocket Real-Time Updates:
- WebSocket endpoint at /ws/opc for real-time task updates
- ConnectionManager for broadcasting to all connected clients
- Frontend WebSocket client with auto-reconnect
- Live updates for task create/update/move/delete actions
- Agent execution status broadcasts

Integration:
- Agent executor starts on dashboard startup
- Task router broadcasts WebSocket updates on all mutations
- Frontend OPC page subscribes to WebSocket and updates UI in real-time
- Agents (PM, CTO, COO) can now execute tasks autonomously

Phase 1 MVP Complete:
✅ PostgreSQL database with full schema
✅ Task CRUD API with automatic time tracking
✅ Kanban board with drag-and-drop
✅ Agent executor service with LLM integration
✅ WebSocket real-time updates
✅ 3 core agents ready to execute

Next: Agent panel UI, email notifications, PDF invoicing

dashboard/frontend/src/lib/opc-ws.js

@@ -0,0 +1,85 @@
+/**
+ * OPC WebSocket Client - Real-time updates
+ */
+
+let ws = null;
+let reconnectTimer = null;
+let listeners = new Set();
+
+export function connect() {
+  if (ws && ws.readyState === WebSocket.OPEN) {
+    return;
+  }
+
+  const protocol = window.location.protocol === "https:" ? "wss:" : "ws:";
+  const wsUrl = `${protocol}//${window.location.host}/ws/opc`;
+
+  ws = new WebSocket(wsUrl);
+
+  ws.onopen = () => {
+    console.log("OPC WebSocket connected");
+    if (reconnectTimer) {
+      clearTimeout(reconnectTimer);
+      reconnectTimer = null;
+    }
+
+    // Send ping every 30 seconds to keep connection alive
+    const pingInterval = setInterval(() => {
+      if (ws && ws.readyState === WebSocket.OPEN) {
+        ws.send("ping");
+      } else {
+        clearInterval(pingInterval);
+      }
+    }, 30000);
+  };
+
+  ws.onmessage = (event) => {
+    try {
+      const message = JSON.parse(event.data);
+      notifyListeners(message);
+    } catch (e) {
+      console.error("Failed to parse WebSocket message:", e);
+    }
+  };
+
+  ws.onerror = (error) => {
+    console.error("WebSocket error:", error);
+  };
+
+  ws.onclose = () => {
+    console.log("OPC WebSocket disconnected");
+    ws = null;
+
+    // Reconnect after 5 seconds
+    reconnectTimer = setTimeout(() => {
+      console.log("Reconnecting WebSocket...");
+      connect();
+    }, 5000);
+  };
+}
+
+export function disconnect() {
+  if (ws) {
+    ws.close();
+    ws = null;
+  }
+  if (reconnectTimer) {
+    clearTimeout(reconnectTimer);
+    reconnectTimer = null;
+  }
+}
+
+export function subscribe(callback) {
+  listeners.add(callback);
+  return () => listeners.delete(callback);
+}
+
+function notifyListeners(message) {
+  listeners.forEach((callback) => {
+    try {
+      callback(message);
+    } catch (e) {
+      console.error("Listener error:", e);
+    }
+  });
+}