fix: Set container user to match host for file ownership

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

docker-compose.yml

@@ -9,6 +9,7 @@ services:
       - .env
     volumes:
       - ./data:/image_drop/data
+    user: "${UID:-1000}:${GID:-1000}"
     healthcheck:
       test: ["CMD-SHELL", "python - <<'PY'\nimport urllib.request,sys\ntry:\n  urllib.request.urlopen('http://localhost:8080/').read(); sys.exit(0)\nexcept Exception:\n  sys.exit(1)\nPY"]
       interval: 30s