Two bugs fixed:
1. search_messages() crashes with OperationalError when user queries
contain FTS5 special characters (+, ", (, {, dangling AND/OR, etc).
Added _sanitize_fts5_query() to strip dangerous operators and a
fallback try-except for edge cases.
2. _append_to_sqlite() in mirror.py creates a new SessionDB per call
but never closes it, leaking SQLite connections. Added finally block
to ensure db.close() is always called.
- Introduced a new channel directory to cache reachable channels/contacts for messaging platforms, enhancing the send_message tool's ability to resolve human-friendly names to numeric IDs.
- Added functionality to mirror sent messages into the target's session transcript, providing context for cross-platform message delivery.
- Updated the send_message tool to support listing available targets and improved error handling for channel resolution.
- Enhanced the gateway to build and refresh the channel directory during startup and at regular intervals, ensuring up-to-date channel information.
