issue #112 fixes and more

lib/screens/channels_screen.dart

@@ -164,7 +164,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
         ),
         body: RefreshIndicator(
           onRefresh: () async {
-            await context.read<MeshCoreConnector>().getChannels();
+            await context.read<MeshCoreConnector>().getChannels(force: true);
           },
           child: () {
             if (connector.isLoadingChannels) {

lib/screens/map_screen.dart

@@ -225,13 +225,15 @@ class _MapScreenState extends State<MapScreen> {
         }
 
         // Re center map after removed markers have loaded
-        if (!_hasInitializedMap && _removedMarkersLoaded && hasMapContent) {
+        if (!_hasInitializedMap && _removedMarkersLoaded) {
           _hasInitializedMap = true;
-          WidgetsBinding.instance.addPostFrameCallback((_) {
-            if (mounted) {
-              _mapController.move(center, initialZoom);
-            }
-          });
+          if (hasMapContent) {
+            WidgetsBinding.instance.addPostFrameCallback((_) {
+              if (mounted) {
+                _mapController.move(center, initialZoom);
+              }
+            });
+          }
         }
 
         final allowBack = !connector.isConnected;
@@ -275,9 +277,7 @@ class _MapScreenState extends State<MapScreen> {
                 ),
               ],
             ),
-            body: !hasMapContent
-                ? _buildEmptyState()
-                : Stack(
+            body: Stack(
                     children: [
                       FlutterMap(
                         mapController: _mapController,
@@ -376,27 +376,6 @@ class _MapScreenState extends State<MapScreen> {
     );
   }
 
-  Widget _buildEmptyState() {
-    return Center(
-      child: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
-        children: [
-          Icon(Icons.location_off, size: 64, color: Colors.grey[400]),
-          const SizedBox(height: 16),
-          Text(
-            context.l10n.map_noNodesWithLocation,
-            style: TextStyle(fontSize: 18, color: Colors.grey[600]),
-          ),
-          const SizedBox(height: 8),
-          Text(
-            context.l10n.map_nodesNeedGps,
-            textAlign: TextAlign.center,
-            style: TextStyle(fontSize: 14, color: Colors.grey[500]),
-          ),
-        ],
-      ),
-    );
-  }
 
   List<Marker> _buildMarkers(List<Contact> contacts, settings) {
     final markers = <Marker>[];

lib/screens/settings_screen.dart

@@ -780,10 +780,15 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
       return;
     }
 
-    if (txPower == null || txPower < 0 || txPower > 22) {
+    final maxTxPower = widget.connector.maxTxPower ?? 22;
+    if (txPower == null || txPower < 0 || txPower > maxTxPower) {
       ScaffoldMessenger.of(
         context,
-      ).showSnackBar(SnackBar(content: Text(l10n.settings_txPowerInvalid)));
+      ).showSnackBar(
+        SnackBar(
+          content: Text('${l10n.settings_txPowerInvalid} (0-$maxTxPower dBm)'),
+        ),
+      );
       return;
     }
 
@@ -932,7 +937,9 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
               decoration: InputDecoration(
                 labelText: l10n.settings_txPower,
                 border: const OutlineInputBorder(),
-                helperText: l10n.settings_txPowerHelper,
+                helperText: widget.connector.maxTxPower != null
+                    ? '${l10n.settings_txPowerHelper} (max: ${widget.connector.maxTxPower} dBm)'
+                    : l10n.settings_txPowerHelper,
               ),
               keyboardType: TextInputType.number,
             ),