Add companion radio stats, adaptive backoff, path hash width, and UI improvements

- Companion radio stats: poll and display noise floor, RSSI, SNR, airtime
  with dedicated ValueNotifier and ref-counted polling
- Adaptive RF-aware TX backoff based on radio conditions instead of fixed 5s
- Variable-width path hash support (1-3 bytes per hop)
- Air activity dot indicator in app bar with tap to open stats screen
- Jump to oldest unread setting for chat screens
- 1s send cooldown on DM and channel messages
- Link style: theme-aware orange, added EmailLinkifier
- New languages: Hungarian, Japanese, Korean
- Remove dead DeviceScreen and BatteryIndicatorChip
- Remove wakelock_plus dependency
- TX power fields now read as signed int8

lib/screens/map_screen.dart

@@ -2191,8 +2191,9 @@ class _MapScreenState extends State<MapScreen> {
                   if (_pathTrace.isNotEmpty)
                     IconButton(
                       onPressed: () {
-                        final hashW =
-                            context.read<MeshCoreConnector>().pathHashByteWidth;
+                        final hashW = context
+                            .read<MeshCoreConnector>()
+                            .pathHashByteWidth;
                         Navigator.push(
                           context,
                           MaterialPageRoute(