Keep Offline Mode pings when a radio drop ends the drive

DEVELOPMENT.md

@@ -1078,6 +1078,7 @@ The app never checks its own version: it sends `APP-<x.y.z>` (store) or `APP-<ep
 - **Session Format**: Each session has a filename (`YYYY-MM-DD.json`), creation timestamp, ping count, device info, and the wardrive data payload
 - **Upload**: Sessions can be uploaded from Settings → Data when connectivity is restored
 - **Non-persistent**: Offline mode is never persisted — always off on app restart. Users must re-enable if needed.
+- **When pings are written**: pings collect in memory (`ApiQueueService` offline buffer, cleared on every app launch) and reach the session file at these points: a 60 s auto-save that runs for as long as Offline Mode is on (it stops only when Offline Mode is turned off or the switch back to online succeeds, never on a save), a snapshot whenever the app is backgrounded, and a final save on mode stop, mode switch, user disconnect and the BLE-drop cleanup after a reconnect gives up. The noise floor session is stored on those same teardowns, so a teardown that skipped the final save left a drive in Session History with no offline file. The final save finalizes the file, so the next connect starts a new one.
 - **Maintenance integration**: When maintenance mode is detected while disconnected, the UI suggests using Offline Mode
 - **Airborne pause**: while the airborne latch is set, no fix is appended to the offline recording (`ApiQueueService.setOfflineRecordingPaused`); the session itself ends through the normal airborne block. See GPS & Zone Validation.
 - **File**: `lib/services/offline_session_service.dart`

lib/providers/app_state_provider.dart

@@ -6662,6 +6662,11 @@ class AppStateProvider extends ChangeNotifier with WidgetsBindingObserver {
     // Stop RX logger
     _rxLogger?.stopWardriving(trigger: 'ble_disconnect');
 
+    // Save offline pings, as disconnect() does. The noise floor session above
+    // is already stored, so skipping this left a drive in History with no
+    // offline file once the unsaved pings were gone (no-op with no pings).
+    await _saveOfflineSession();
+
     // Force upload any pending items BEFORE releasing session
     if (flushQueue && _apiService.hasSession) {
       debugLog('[CONN] Flushing API queue before session release');
@@ -9352,6 +9357,9 @@ class AppStateProvider extends ChangeNotifier with WidgetsBindingObserver {
 
       // 5. Auth successful - update state
       switchSucceeded = true;
+      // Offline Mode is off for good now (the finally only rolls back a
+      // failed switch), so its auto-save stops here.
+      _stopOfflineAutoSaveTimer();
 
       // 6. Update regional channels from auth response
       final channels = result['channels'];
@@ -9466,7 +9474,9 @@ class AppStateProvider extends ChangeNotifier with WidgetsBindingObserver {
   String? get _offlineDeviceName => _isAnonymousRenamed
       ? 'Anonymous'
       : (_meshCoreConnection?.selfInfo?.name ??
-          connectedDeviceName?.replaceFirst('MeshCore-', ''));
+          connectedDeviceName?.replaceFirst('MeshCore-', '') ??
+          // A reconnect that gave up has already dropped the connection.
+          _displayDeviceName);
 
   /// Save accumulated offline pings to a session file
   Future<void> _saveOfflineSession() async {
@@ -9492,7 +9502,9 @@ class AppStateProvider extends ChangeNotifier with WidgetsBindingObserver {
       devicePublicKey: _devicePublicKey,
       deviceName: offlineDeviceName,
       contactUri: _offlineContactUri,
-      radioConfig: _meshCoreConnection?.selfInfo?.radioConfigApi,
+      // The remembered config covers a reconnect that gave up, which has
+      // already dropped the connection.
+      radioConfig: liveRadioConfig ?? _lastRadioConfig,
       deviceModel: _meshCoreConnection?.deviceModel?.manufacturer ??
           _meshCoreConnection?.deviceInfo?.manufacturer ??
           _manufacturerString,
@@ -9501,7 +9513,9 @@ class AppStateProvider extends ChangeNotifier with WidgetsBindingObserver {
     );
     _offlineSessionService.finalizeCurrentSession();
     debugLog('[APP] Saved offline session with ${pings.length} pings');
-    _stopOfflineAutoSaveTimer();
+    // The auto-save keeps running: Offline Mode is still on, and the next
+    // connect or mode start in this stint needs it. It stops when Offline
+    // Mode is turned off.
     notifyListeners();
   }