Replace CLI parameters with environment variables, keeping only --multi-user and --help
Environment variables:
- PENPOT_MCP_SERVER_PORT (new, replaces CLI param)
- PENPOT_MCP_WEBSOCKET_PORT (new)
- PENPOT_MCP_REPL_PORT (new)
- PENPOT_MCP_SERVER_ADDRESS (new)
- PENPOT_MCP_REMOTE_MODE (existing)
- PENPOT_MCP_LOG_LEVEL (renamed from LOG_LEVEL, replaces CLI param)
- PENPOT_MCP_LOG_DIR (renamed from LOG_DIR, replaces CLI param)
- PENPOT_MCP_PLUGIN_SERVER_LISTEN_ADDRESS (renamed from PENPOT_MCP_PLUGIN_SERVER_ALLOWED_HOSTS)
Additional changes:
- Plugin now constructs WebSocket URL from server address and port (replaces PENPOT_MCP_WEBSOCKET_URL)
- Use configured server address in all startup log messages
- Document all configuration options in README.md
