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/channel_message_path_screen.dart

@@ -64,8 +64,9 @@ class ChannelMessagePathScreen extends StatelessWidget {
                       flipPathAround: true,
                       reversePathAround:
                           !(!channelMessage && !message.isOutgoing),
-                      pathHashByteWidth:
-                          context.read<MeshCoreConnector>().pathHashByteWidth,
+                      pathHashByteWidth: context
+                          .read<MeshCoreConnector>()
+                          .pathHashByteWidth,
                     ),
                   ),
                 ),