Add base kubernetes support 4

frontend/Dockerfile.kubernetes

@@ -43,10 +43,10 @@ set -e
 # Handle VITE_API_URL specially to preserve empty values
 # If VITE_API_URL is unset, use default; if empty, preserve empty; otherwise use value
 if [ -z "${VITE_API_URL+x}" ]; then
-  export VITE_API_URL="http://gateway-service:8000"
+  export VITE_API_URL="/api"
 elif [ -z "$VITE_API_URL" ]; then
-  # If VITE_API_URL is explicitly set to empty string, preserve it
-  export VITE_API_URL=""
+  # If VITE_API_URL is explicitly set to empty string, use relative API path
+  export VITE_API_URL="/api"
 fi
 
 # Default values for other environment variables