Previously a blocked join just dropped the socket, so the MC client
showed 'Internal Exception: SocketException: Connection reset'.
Now when next_state=2 (login), the proxy sends a proper Login
Disconnect (0x00) packet containing a JSON chat component, and the
client displays the message on its disconnect screen.
- block_message added to config (default Korean message); editable
in Settings UI as a textarea
- build_login_disconnect() encodes (varint length)+(0x00)+(JSON str)
- Status/ping (next_state=1) still silently dropped so the proxy
presence is not announced to scanners
- Backward-compat: load_config() backfills block_message on old files
claude-bot
75c4242365