feat(#18): inline Radio Settings form into its pane

Bring radio config up a level: render the form directly in the Radio Settings pane with a full-width Save button, instead of a tile that opens a dialog. _RadioSettingsDialog -> _RadioSettingsForm; build returns an inline Column of the (verbatim) fields + Save; _saveSettings drops the Navigator.pop (no dialog), which also resolves the unguarded-pop-after-await finding. Removed _showRadioSettings. Field widgets, controllers, preset matching, and off-grid snapshot logic unchanged.

Key the form on the device's current radio values (freq/bw/sf/cr/txpower/clientRepeat) so a device-reported change re-seeds it -- the dialog got this for free by reopening; the persistent inline form needs the key.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/screens/settings_screen.dart

@@ -138,21 +138,33 @@ class _SettingsScreenState extends State<SettingsScreen> {
       padding: const EdgeInsets.all(16),
       children: [
         Card(
+          child: Padding(
+            padding: const EdgeInsets.all(16),
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-              ListTile(
-                leading: const Icon(Icons.radio),
-                title: Text(l10n.settings_radioSettings),
-                subtitle: Text(l10n.settings_radioSettingsSubtitle),
-                trailing: const Icon(Icons.chevron_right),
-                onTap: () => _showRadioSettings(context, connector),
+                Text(
+                  l10n.settings_radioSettings,
+                  style: const TextStyle(
+                    fontSize: 18,
+                    fontWeight: FontWeight.bold,
+                  ),
+                ),
+                const SizedBox(height: 8),
+                _RadioSettingsForm(
+                  key: ValueKey(
+                    '${connector.currentFreqHz}-${connector.currentBwHz}-'
+                    '${connector.currentSf}-${connector.currentCr}-'
+                    '${connector.currentTxPower}-${connector.clientRepeat}',
+                  ),
+                  connector: connector,
                 ),
-              const Divider(height: 1),
-              _PathHashSizeTile(connector: connector),
               ],
             ),
           ),
+        ),
+        const SizedBox(height: 16),
+        Card(child: _PathHashSizeTile(connector: connector)),
       ],
     );
   }
@@ -663,13 +675,6 @@ class _SettingsScreenState extends State<SettingsScreen> {
     );
   }
 
-  void _showRadioSettings(BuildContext context, MeshCoreConnector connector) {
-    showDialog(
-      context: context,
-      builder: (context) => _RadioSettingsDialog(connector: connector),
-    );
-  }
-
   void _editLocation(BuildContext context, MeshCoreConnector connector) {
     final l10n = context.l10n;
     final latController = TextEditingController();
@@ -1367,16 +1372,16 @@ class _AutoAddSectionState extends State<_AutoAddSection> {
   }
 }
 
-class _RadioSettingsDialog extends StatefulWidget {
+class _RadioSettingsForm extends StatefulWidget {
   final MeshCoreConnector connector;
 
-  const _RadioSettingsDialog({required this.connector});
+  const _RadioSettingsForm({super.key, required this.connector});
 
   @override
-  State<_RadioSettingsDialog> createState() => _RadioSettingsDialogState();
+  State<_RadioSettingsForm> createState() => _RadioSettingsFormState();
 }
 
-class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
+class _RadioSettingsFormState extends State<_RadioSettingsForm> {
   final _frequencyController = TextEditingController();
   LoRaBandwidth _bandwidth = LoRaBandwidth.bw125;
   LoRaSpreadingFactor _spreadingFactor = LoRaSpreadingFactor.sf7;
@@ -1763,7 +1768,6 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
         content: Text(l10n.settings_error(e.toString())),
       );
     }
-    Navigator.pop(context);
   }
 
   String _presetLabel(int? index) {
@@ -1803,10 +1807,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
   @override
   Widget build(BuildContext context) {
     final l10n = context.l10n;
-    return AlertDialog(
-      title: Text(l10n.settings_radioSettings),
-      content: SingleChildScrollView(
-        child: Column(
+    return Column(
       mainAxisSize: MainAxisSize.min,
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
@@ -1839,9 +1840,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
             border: const OutlineInputBorder(),
             helperText: l10n.settings_frequencyHelper,
           ),
-              keyboardType: const TextInputType.numberWithOptions(
-                decimal: true,
-              ),
+          keyboardType: const TextInputType.numberWithOptions(decimal: true),
         ),
         const SizedBox(height: 16),
         DropdownButtonFormField<LoRaBandwidth>(
@@ -1851,9 +1850,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
             border: const OutlineInputBorder(),
           ),
           items: LoRaBandwidth.values
-                  .map(
-                    (bw) => DropdownMenuItem(value: bw, child: Text(bw.label)),
-                  )
+              .map((bw) => DropdownMenuItem(value: bw, child: Text(bw.label)))
               .toList(),
           onChanged: (value) {
             if (value != null) {
@@ -1873,9 +1870,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
             border: const OutlineInputBorder(),
           ),
           items: LoRaSpreadingFactor.values
-                  .map(
-                    (sf) => DropdownMenuItem(value: sf, child: Text(sf.label)),
-                  )
+              .map((sf) => DropdownMenuItem(value: sf, child: Text(sf.label)))
               .toList(),
           onChanged: (value) {
             if (value != null) {
@@ -1883,9 +1878,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
                 _spreadingFactor = value;
                 _syncPresetSelection();
               });
-                  _logRadioSettingsState(
-                    'Manual settings edit: spreading factor',
-                  );
+              _logRadioSettingsState('Manual settings edit: spreading factor');
             }
           },
         ),
@@ -1897,9 +1890,7 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
             border: const OutlineInputBorder(),
           ),
           items: LoRaCodingRate.values
-                  .map(
-                    (cr) => DropdownMenuItem(value: cr, child: Text(cr.label)),
-                  )
+              .map((cr) => DropdownMenuItem(value: cr, child: Text(cr.label)))
               .toList(),
           onChanged: (value) {
             if (value != null) {
@@ -1934,15 +1925,15 @@ class _RadioSettingsDialogState extends State<_RadioSettingsDialog> {
             contentPadding: EdgeInsets.zero,
           ),
         ],
-          ],
-        ),
+        const SizedBox(height: 16),
+        SizedBox(
+          width: double.infinity,
+          child: FilledButton.icon(
+            onPressed: _saveSettings,
+            icon: const Icon(Icons.save_outlined),
+            label: Text(l10n.common_save),
           ),
-      actions: [
-        TextButton(
-          onPressed: () => Navigator.pop(context),
-          child: Text(l10n.common_cancel),
         ),
-        FilledButton(onPressed: _saveSettings, child: Text(l10n.common_save)),
       ],
     );
   }