feat: Add presence heartbeat for Matrix online status

- matrix-gateway: POST /internal/matrix/presence/online endpoint
- usePresenceHeartbeat hook with activity tracking
- Auto away after 5 min inactivity
- Offline on page close/visibility change
- Integrated in MatrixChatRoom component

services/agent-runtime/messaging_client.py

@@ -0,0 +1,74 @@
+import httpx
+import os
+from models import ChannelMessage
+from datetime import datetime
+
+MESSAGING_SERVICE_URL = os.getenv("MESSAGING_SERVICE_URL", "http://messaging-service:7004")
+
+async def get_channel_messages(channel_id: str, limit: int = 50) -> list[ChannelMessage]:
+    """
+    Fetch recent messages from channel
+    
+    Returns list of ChannelMessage objects for context
+    """
+    try:
+        async with httpx.AsyncClient(timeout=10.0) as client:
+            response = await client.get(
+                f"{MESSAGING_SERVICE_URL}/api/messaging/channels/{channel_id}/messages",
+                params={"limit": limit}
+            )
+            response.raise_for_status()
+            data = response.json()
+            
+            messages = []
+            for msg in data:
+                try:
+                    messages.append(ChannelMessage(
+                        sender_id=msg.get("sender_id", "unknown"),
+                        sender_type=msg.get("sender_type", "human"),
+                        content=msg.get("body", msg.get("content_preview", "")),
+                        created_at=datetime.fromisoformat(msg.get("created_at", datetime.now().isoformat()).replace('Z', '+00:00'))
+                    ))
+                except Exception as e:
+                    print(f"⚠️ Error parsing message: {e}")
+                    continue
+            
+            print(f"✅ Fetched {len(messages)} messages from channel {channel_id}")
+            return messages
+    except httpx.HTTPStatusError as e:
+        print(f"⚠️ HTTP error fetching messages: {e.response.status_code}")
+        return []
+    except Exception as e:
+        print(f"⚠️ Error fetching messages: {e}")
+        return []
+
+async def post_message(agent_id: str, channel_id: str, text: str) -> bool:
+    """
+    Post agent reply to channel
+    
+    Returns True if successful, False otherwise
+    """
+    try:
+        async with httpx.AsyncClient(timeout=10.0) as client:
+            response = await client.post(
+                f"{MESSAGING_SERVICE_URL}/internal/agents/{agent_id}/post-to-channel",
+                json={
+                    "channel_id": channel_id,
+                    "text": text
+                }
+            )
+            response.raise_for_status()
+            print(f"✅ Posted message to channel {channel_id}")
+            return True
+    except httpx.HTTPStatusError as e:
+        print(f"❌ HTTP error posting message: {e.response.status_code}")
+        if e.response.status_code == 404:
+            print(f"   Endpoint not found. You may need to add it to messaging-service.")
+        return False
+    except Exception as e:
+        print(f"❌ Error posting message: {e}")
+        return False
+
+
+
+