- Add comprehensive XMPP settings schema to plugin.json
- Implement configuration struct with validation and helper methods
- Add configurable username prefix for XMPP users
- Set up logger in Plugin struct following Matrix bridge pattern
- Update KV store constants to use XMPP terminology
- Replace Matrix references with XMPP equivalents in test helpers
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
