feat(#275): per-channel notify mode from the channel ellipsis menu

Extracts the #262 notify-mode selector out of channels_screen into a shared
widgets/channel_notify_mode.dart (key, icon, label, dialog) and points both
entry points at it, so the Channels list and the in-channel menu cannot drift.
Same PSK-keyed storage; no new settings.

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

lib/screens/channel_chat_screen.dart

@@ -24,6 +24,7 @@ import '../models/channel_message.dart';
 import '../models/translation_support.dart';
 import '../models/app_settings.dart';
 import '../services/app_settings_service.dart';
+import '../widgets/channel_notify_mode.dart';
 import '../services/block_service.dart';
 import '../services/chat_text_scale_service.dart';
 import '../services/translation_service.dart';
@@ -424,13 +425,33 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
           PopupMenuButton<String>(
             icon: const Icon(Icons.more_vert),
             onSelected: (value) {
-              if (value == 'clearChat') {
+              if (value == 'notifications') {
+                showChannelNotifyModeDialog(context, widget.channel);
+              } else if (value == 'clearChat') {
                 context.read<MeshCoreConnector>().clearMessagesForChannel(
                   _currentChannel.index,
                 );
               }
             },
             itemBuilder: (context) => [
+              PopupMenuItem(
+                value: 'notifications',
+                child: Row(
+                  children: [
+                    Icon(
+                      channelNotifyModeIcon(
+                        context.read<AppSettingsService>().channelNotifyMode(
+                          identityKey: channelNotifyKeyFor(widget.channel),
+                          channelName: widget.channel.name,
+                        ),
+                      ),
+                      size: 20,
+                    ),
+                    const SizedBox(width: 12),
+                    Text(context.l10n.channels_notifications),
+                  ],
+                ),
+              ),
               PopupMenuItem(
                 value: 'clearChat',
                 child: Row(

lib/screens/channels_screen.dart

@@ -13,7 +13,6 @@ import '../connector/meshcore_connector.dart';
 import '../l10n/l10n.dart';
 import '../services/app_settings_service.dart';
 import '../services/ui_view_state_service.dart';
-import '../models/app_settings.dart';
 import '../models/channel.dart';
 import '../models/community.dart';
 import '../storage/community_store.dart';
@@ -27,6 +26,7 @@ import '../widgets/app_shell.dart';
 import '../widgets/channel_drawer_list.dart';
 import '../widgets/sync_progress_overlay.dart';
 import '../widgets/unread_badge.dart';
+import '../widgets/channel_notify_mode.dart';
 import '../helpers/snack_bar_builder.dart';
 import 'channel_chat_screen.dart';
 import 'community_qr_scanner_screen.dart';
@@ -468,71 +468,6 @@ class _ChannelsScreenState extends State<ChannelsScreen>
     );
   }
 
-  /// Notify-mode storage key for [channel]: its PSK identity, so the setting
-  /// survives a rename and does not follow a reused slot (#259).
-  String _notifyKeyFor(Channel channel) => AppSettings.channelNotifyKey(
-    channelIndex: channel.index,
-    pskHex: channel.pskHex,
-  );
-
-  IconData _notifyModeIcon(ChannelNotifyMode mode) {
-    switch (mode) {
-      case ChannelNotifyMode.all:
-        return Icons.notifications_outlined;
-      case ChannelNotifyMode.mentionsOnly:
-        return Icons.alternate_email;
-      case ChannelNotifyMode.off:
-        return Icons.notifications_off_outlined;
-    }
-  }
-
-  String _notifyModeLabel(BuildContext context, ChannelNotifyMode mode) {
-    switch (mode) {
-      case ChannelNotifyMode.all:
-        return context.l10n.channels_notifyAll;
-      case ChannelNotifyMode.mentionsOnly:
-        return context.l10n.channels_notifyMentionsOnly;
-      case ChannelNotifyMode.off:
-        return context.l10n.channels_notifyOff;
-    }
-  }
-
-  void _showNotifyModeDialog(BuildContext context, Channel channel) {
-    final settingsService = context.read<AppSettingsService>();
-    final identityKey = _notifyKeyFor(channel);
-    final current = settingsService.channelNotifyMode(
-      identityKey: identityKey,
-      channelName: channel.name,
-    );
-
-    showDialog<void>(
-      context: context,
-      builder: (dialogContext) => AlertDialog(
-        title: Text(dialogContext.l10n.channels_notifications),
-        contentPadding: const EdgeInsets.symmetric(vertical: 8),
-        content: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            for (final mode in ChannelNotifyMode.values)
-              ListTile(
-                leading: Icon(_notifyModeIcon(mode)),
-                title: Text(_notifyModeLabel(dialogContext, mode)),
-                trailing: mode == current ? const Icon(Icons.check) : null,
-                onTap: () async {
-                  Navigator.pop(dialogContext);
-                  await settingsService.setChannelNotifyMode(
-                    identityKey: identityKey,
-                    channelName: channel.name,
-                    mode: mode,
-                  );
-                },
-              ),
-          ],
-        ),
-      ),
-    );
-  }
-
   void _showChannelActions(
     BuildContext context,
     MeshCoreConnector connector,
@@ -542,7 +477,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
     final parentContext = context;
     final settingsService = context.read<AppSettingsService>();
     final notifyMode = settingsService.channelNotifyMode(
-      identityKey: _notifyKeyFor(channel),
+      identityKey: channelNotifyKeyFor(channel),
       channelName: channel.name,
     );
 
@@ -575,14 +510,14 @@ class _ChannelsScreenState extends State<ChannelsScreen>
               },
             ),
             ListTile(
-              leading: Icon(_notifyModeIcon(notifyMode)),
+              leading: Icon(channelNotifyModeIcon(notifyMode)),
               title: Text(context.l10n.channels_notifications),
-              subtitle: Text(_notifyModeLabel(context, notifyMode)),
+              subtitle: Text(channelNotifyModeLabel(context, notifyMode)),
               onTap: () async {
                 Navigator.pop(sheetContext);
                 await Future.delayed(const Duration(milliseconds: 100));
                 if (parentContext.mounted) {
-                  _showNotifyModeDialog(parentContext, channel);
+                  showChannelNotifyModeDialog(parentContext, channel);
                 }
               },
             ),

lib/widgets/channel_notify_mode.dart

@@ -0,0 +1,76 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../l10n/l10n.dart';
+import '../models/app_settings.dart';
+import '../models/channel.dart';
+import '../services/app_settings_service.dart';
+
+/// Shared per-channel notify-mode affordance (#262), reachable both from the
+/// Channels list and from inside a channel's chat (#275). Single implementation
+/// so the two entry points cannot drift.
+
+/// Notify-mode storage key for [channel]: its PSK identity, so the setting
+/// survives a rename and does not follow a reused slot (#259).
+String channelNotifyKeyFor(Channel channel) => AppSettings.channelNotifyKey(
+  channelIndex: channel.index,
+  pskHex: channel.pskHex,
+);
+
+IconData channelNotifyModeIcon(ChannelNotifyMode mode) {
+  switch (mode) {
+    case ChannelNotifyMode.all:
+      return Icons.notifications_outlined;
+    case ChannelNotifyMode.mentionsOnly:
+      return Icons.alternate_email;
+    case ChannelNotifyMode.off:
+      return Icons.notifications_off_outlined;
+  }
+}
+
+String channelNotifyModeLabel(BuildContext context, ChannelNotifyMode mode) {
+  switch (mode) {
+    case ChannelNotifyMode.all:
+      return context.l10n.channels_notifyAll;
+    case ChannelNotifyMode.mentionsOnly:
+      return context.l10n.channels_notifyMentionsOnly;
+    case ChannelNotifyMode.off:
+      return context.l10n.channels_notifyOff;
+  }
+}
+
+void showChannelNotifyModeDialog(BuildContext context, Channel channel) {
+  final settingsService = context.read<AppSettingsService>();
+  final identityKey = channelNotifyKeyFor(channel);
+  final current = settingsService.channelNotifyMode(
+    identityKey: identityKey,
+    channelName: channel.name,
+  );
+
+  showDialog<void>(
+    context: context,
+    builder: (dialogContext) => AlertDialog(
+      title: Text(dialogContext.l10n.channels_notifications),
+      contentPadding: const EdgeInsets.symmetric(vertical: 8),
+      content: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          for (final mode in ChannelNotifyMode.values)
+            ListTile(
+              leading: Icon(channelNotifyModeIcon(mode)),
+              title: Text(channelNotifyModeLabel(dialogContext, mode)),
+              trailing: mode == current ? const Icon(Icons.check) : null,
+              onTap: () async {
+                Navigator.pop(dialogContext);
+                await settingsService.setChannelNotifyMode(
+                  identityKey: identityKey,
+                  channelName: channel.name,
+                  mode: mode,
+                );
+              },
+            ),
+        ],
+      ),
+    ),
+  );
+}