fix: make Docker container UID/GID configurable

Add UID and GID build arguments to Dockerfiles to allow matching the
container user to the host user. This fixes file permission issues when
mounting host directories as volumes.

Default remains 1001 for backward compatibility. To match host user:
  UID=$(id -u) GID=$(id -g) docker-compose build

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.dev-server.yml

@@ -17,6 +17,11 @@ services:
     build:
       context: .
       dockerfile: Dockerfile.dev
+      args:
+        # Match container user to host user for mounted volume permissions
+        # Override with: UID=$(id -u) GID=$(id -g) docker-compose build
+        UID: ${UID:-1001}
+        GID: ${GID:-1001}
     container_name: automaker-dev-server-only
     restart: unless-stopped
     ports: