feat(city-map): Add 2D City Map with coordinates and agent presence

- Add migration 013_city_map_coordinates.sql with map coordinates, zones, and agents table
- Add /city/map API endpoint in city-service
- Add /city/agents and /city/agents/online endpoints
- Extend presence aggregator to include agents[] in snapshot
- Add AgentsSource for fetching agent data from DB
- Create CityMap component with interactive room tiles
- Add useCityMap hook for fetching map data
- Update useGlobalPresence to include agents
- Add map/list view toggle on /city page
- Add agent badges to room cards and map tiles

services/matrix-presence-aggregator/app/agents_source.py

@@ -0,0 +1,92 @@
+"""Agents data source from PostgreSQL"""
+from sqlalchemy import create_engine, text
+from typing import List, Dict
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class AgentsSource:
+    """Fetches agent data from PostgreSQL"""
+    
+    def __init__(self, db_dsn: str):
+        self.engine = create_engine(db_dsn)
+    
+    def get_online_agents(self) -> List[Dict]:
+        """
+        Get all online/busy agents.
+        
+        Returns list of dicts with:
+        - agent_id
+        - display_name
+        - kind
+        - status
+        - room_id (current_room_id)
+        - color
+        """
+        query = text("""
+            SELECT 
+                id as agent_id,
+                display_name,
+                kind,
+                status,
+                current_room_id as room_id,
+                color
+            FROM agents
+            WHERE status IN ('online', 'busy')
+            ORDER BY display_name
+        """)
+        
+        try:
+            with self.engine.connect() as conn:
+                rows = conn.execute(query).mappings().all()
+                return [dict(r) for r in rows]
+        except Exception as e:
+            logger.error(f"Failed to get online agents: {e}")
+            return []
+    
+    def get_agents_by_room(self, room_id: str) -> List[Dict]:
+        """Get agents in a specific room"""
+        query = text("""
+            SELECT 
+                id as agent_id,
+                display_name,
+                kind,
+                status,
+                current_room_id as room_id,
+                color
+            FROM agents
+            WHERE current_room_id = :room_id AND status != 'offline'
+            ORDER BY display_name
+        """)
+        
+        try:
+            with self.engine.connect() as conn:
+                rows = conn.execute(query, {"room_id": room_id}).mappings().all()
+                return [dict(r) for r in rows]
+        except Exception as e:
+            logger.error(f"Failed to get agents for room {room_id}: {e}")
+            return []
+    
+    def get_all_agents(self) -> List[Dict]:
+        """Get all agents (including offline)"""
+        query = text("""
+            SELECT 
+                id as agent_id,
+                display_name,
+                kind,
+                status,
+                current_room_id as room_id,
+                color
+            FROM agents
+            ORDER BY display_name
+        """)
+        
+        try:
+            with self.engine.connect() as conn:
+                rows = conn.execute(query).mappings().all()
+                return [dict(r) for r in rows]
+        except Exception as e:
+            logger.error(f"Failed to get all agents: {e}")
+            return []
+