Extends signal metrics support to BLE interfaces by implementing RSSI
tracking for BLE peer connections. Uses existing KotlinBLEBridge to
query the last RSSI value from connected peers via the Android GATT
connection.
Changes:
- Add getPeerRssi() method to KotlinBLEBridge for querying BLE RSSI
- Add get_peer_rssi() to AndroidBLEDriver with last-receive tracking
- Add get_rssi() to AndroidBLEInterface wrapper classes
- Handle BLEPeerInterface in signal_quality.py for proper RSSI extraction
- Add 16 comprehensive unit tests for new functionality
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
