Agent ships without City/Country MMDB in the binary; Docker images COPY
databases into data_dir, bare installs seed via download on first start.
Server keeps Country-only embed for optional MaxMind control-plane use.
Also harden fetch script nonempty check and reject non-file MMDB paths.
- Implement configurable FRPS WebUI switch and custom port setting (relay_frps_web_ui_port) in system configs.
- Integrate settings into Relay Node detail manage page instead of global settings.
- Dynamically query server version to select matching Docker image tag for Relay installation.
- Clean up legacy code and fix backend linter/test warnings.