fix: Add API proxy for MinIO assets to work without assets.daarion.space DNS

- Add /api/assets/[...path] proxy route in Next.js
- Add /assets/proxy/{path} endpoint in city-service
- Update normalizeAssetUrl to convert assets.daarion.space URLs to /api/assets/...
- This allows assets to work even if DNS for assets.daarion.space is not configured

services/city-service/routes_city.py

@@ -324,6 +324,51 @@ async def update_agent_visibility_endpoint(
 # Assets & Branding API (Task 042)
 # =============================================================================
 
+@router.get("/assets/proxy/{path:path}")
+async def proxy_asset(path: str):
+    """
+    Proxy endpoint for serving MinIO assets.
+    Allows serving assets through /api/assets/... instead of requiring assets.daarion.space DNS.
+    """
+    from lib.assets_client import get_minio_client, ASSETS_BUCKET
+    from fastapi.responses import StreamingResponse
+    import io
+    
+    try:
+        client = get_minio_client()
+        
+        # Get object from MinIO
+        response = client.get_object(ASSETS_BUCKET, path)
+        
+        # Read data
+        data = response.read()
+        response.close()
+        response.release_conn()
+        
+        # Determine content type
+        content_type = "application/octet-stream"
+        if path.endswith('.png'):
+            content_type = 'image/png'
+        elif path.endswith('.jpg') or path.endswith('.jpeg'):
+            content_type = 'image/jpeg'
+        elif path.endswith('.webp'):
+            content_type = 'image/webp'
+        elif path.endswith('.gif'):
+            content_type = 'image/gif'
+        
+        return StreamingResponse(
+            io.BytesIO(data),
+            media_type=content_type,
+            headers={
+                'Cache-Control': 'public, max-age=86400, immutable',
+                'Access-Control-Allow-Origin': '*',
+            }
+        )
+    except Exception as e:
+        logger.error(f"Failed to proxy asset {path}: {e}")
+        raise HTTPException(status_code=404, detail="Asset not found")
+
+
 @router.post("/assets/upload")
 async def upload_asset(
     file: UploadFile = File(...),