fix(nodes): Normalize Router/Swapper endpoints and fix NODE2 display

Major changes:
- Normalize get_node_endpoints to use ENV vars (ROUTER_BASE_URL, SWAPPER_BASE_URL)
- Remove node_id-based URL selection logic
- Add fallback direct API call in get_node_swapper_detail
- Fix Swapper API endpoint (/models instead of /api/v1/models)
- Add router_healthy and router_version to node_heartbeat fallback
- Add ENV vars to docker-compose for Router/Swapper URLs

Documentation:
- Add TASK_PHASE_NODE2_ROUTER_SWAPPER_FIX.md with full task description
- Add NODE2_GUARDIAN_SETUP.md with setup instructions

This fixes:
- Swapper models not showing for NODE1 and NODE2
- DAGI Router agents not showing for NODE2
- Router/Swapper showing as Down/Degraded when they're actually up

services/city-service/repo_city.py

@@ -3345,36 +3345,41 @@ async def get_node_metrics_current(node_id: str) -> Optional[Dict[str, Any]]:
 
 async def get_node_endpoints(node_id: str) -> Dict[str, str]:
     """
-    Отримати URL endpoints для конкретної ноди.
-    Якщо в БД немає значень — підставляє дефолти на основі node_id.
+    Отримати URL endpoints для DAGI Router та Swapper Service.
+    
+    Використовує ENV змінні для базових URL (один для всіх нод у проді).
+    Якщо в БД є специфічні URL для ноди - використовує їх, інакше - ENV дефолти.
+    
+    ENV змінні:
+    - ROUTER_BASE_URL (default: http://dagi-router:9102 для проді)
+    - SWAPPER_BASE_URL (default: http://swapper-service:8890 для проді)
+    
+    Для DEV (локальний запуск на Mac):
+    - ROUTER_BASE_URL=http://localhost:9102
+    - SWAPPER_BASE_URL=http://localhost:8890
     """
     pool = await get_pool()
     
+    # Get node-specific URLs from DB if exist
     row = await pool.fetchrow("""
         SELECT router_url, swapper_url
         FROM node_cache
         WHERE node_id = $1
     """, node_id)
     
-    # Determine defaults based on node_id
-    is_node2 = "node-2" in node_id.lower() or "macbook" in node_id.lower()
+    # Get base URLs from ENV (one for all nodes in production)
+    router_base = os.getenv("ROUTER_BASE_URL", "http://dagi-router:9102")
+    swapper_base = os.getenv("SWAPPER_BASE_URL", "http://swapper-service:8890")
     
-    if is_node2:
-        # NODE2 defaults (localhost or IP-based)
-        defaults = {
-            "router_url": "http://localhost:9102",
-            "swapper_url": "http://localhost:8890"
-        }
-    else:
-        # NODE1 defaults (Docker-based)
-        defaults = {
-            "router_url": "http://dagi-router:9102",
-            "swapper_url": "http://swapper-service:8890"
-        }
+    defaults = {
+        "router_url": router_base,
+        "swapper_url": swapper_base
+    }
     
     if not row:
         return defaults
     
+    # Use DB values if present, otherwise fallback to ENV defaults
     return {
         "router_url": row["router_url"] or defaults["router_url"],
         "swapper_url": row["swapper_url"] or defaults["swapper_url"]
@@ -3863,7 +3868,11 @@ async def node_heartbeat(
                 swapper_state = CASE 
                     WHEN $12::jsonb IS NOT NULL THEN $12::jsonb 
                     ELSE swapper_state 
-                END
+                END,
+                router_healthy = COALESCE($13::boolean, router_healthy),
+                router_version = COALESCE($14, router_version),
+                router_url = COALESCE($15, router_url),
+                swapper_url = COALESCE($16, swapper_url)
             WHERE node_id = $1
         """, 
             node_id,
@@ -3877,7 +3886,11 @@ async def node_heartbeat(
             metrics.get("swapper_healthy"),
             metrics.get("swapper_models_loaded"),
             metrics.get("swapper_models_total"),
-            swapper_state_json
+            swapper_state_json,
+            metrics.get("router_healthy"),
+            metrics.get("router_version"),
+            metrics.get("router_url"),
+            metrics.get("swapper_url")
         )
         
         return {