Add global Midnight Aurora Open WebUI theme

compose.yaml

@@ -342,6 +342,10 @@ services:
     restart: unless-stopped
     volumes:
       - open-webui-data:/app/backend/data
+      # Upstream-supported static customization hooks. Keeping these files in
+      # the repository makes the global dark theme reproducible and update-safe.
+      - ./platform/openwebui/theme/custom.css:/app/build/static/custom.css:ro
+      - ./platform/openwebui/theme/loader.js:/app/build/static/loader.js:ro
     environment:
       WEBUI_SECRET_KEY: "${WEBUI_SECRET_KEY:?WEBUI_SECRET_KEY is required}"
       OLLAMA_BASE_URL: ""