fix(mobile): use pink dots for unread activity

mobile/lib/features/activity/activity_page/inbox_row.dart

@@ -258,7 +258,7 @@ class _InboxRow extends HookConsumerWidget {
                                           height: 6,
                                           decoration: BoxDecoration(
                                             shape: BoxShape.circle,
-                                            color: context.colors.primary,
+                                            color: context.appColors.unread,
                                           ),
                                         ),
                                       ],

mobile/lib/features/channels/channels_page/channel_tile.dart

@@ -118,7 +118,7 @@ class _ChannelTile extends ConsumerWidget {
                   height: 6,
                   decoration: BoxDecoration(
                     shape: BoxShape.circle,
-                    color: context.colors.primary,
+                    color: context.appColors.unread,
                   ),
                 ),
               ),

mobile/lib/shared/theme/app_colors.dart

@@ -5,6 +5,9 @@ class AppColors extends ThemeExtension<AppColors> {
   final Color success;
   final Color warning;
   final Color accent;
+
+  /// Unread activity dots, independent of the selected accent.
+  final Color unread;
   final Color huddleDrawerSurface;
   final Color huddleControlSurface;
   final Color onHuddleDrawer;
@@ -18,6 +21,7 @@ class AppColors extends ThemeExtension<AppColors> {
     required this.success,
     required this.warning,
     required this.accent,
+    required this.unread,
     required this.huddleDrawerSurface,
     required this.huddleControlSurface,
     required this.onHuddleDrawer,
@@ -29,6 +33,7 @@ class AppColors extends ThemeExtension<AppColors> {
     Color? success,
     Color? warning,
     Color? accent,
+    Color? unread,
     Color? huddleDrawerSurface,
     Color? huddleControlSurface,
     Color? onHuddleDrawer,
@@ -37,6 +42,7 @@ class AppColors extends ThemeExtension<AppColors> {
     success: success ?? this.success,
     warning: warning ?? this.warning,
     accent: accent ?? this.accent,
+    unread: unread ?? this.unread,
     huddleDrawerSurface: huddleDrawerSurface ?? this.huddleDrawerSurface,
     huddleControlSurface: huddleControlSurface ?? this.huddleControlSurface,
     onHuddleDrawer: onHuddleDrawer ?? this.onHuddleDrawer,
@@ -50,6 +56,7 @@ class AppColors extends ThemeExtension<AppColors> {
       success: Color.lerp(success, other.success, t)!,
       warning: Color.lerp(warning, other.warning, t)!,
       accent: Color.lerp(accent, other.accent, t)!,
+      unread: Color.lerp(unread, other.unread, t)!,
       huddleDrawerSurface: Color.lerp(
         huddleDrawerSurface,
         other.huddleDrawerSurface,

mobile/lib/shared/theme/app_theme.dart

@@ -40,6 +40,7 @@ class AppTheme {
       success: const Color(0xFF218358), // Desktop green-11
       warning: const Color(0xFFAB6400), // Desktop amber-11
       accent: scheme.tertiary,
+      unread: const Color(0xFFDF1E85), // Desktop status-unread (magenta-9)
       huddleDrawerSurface: const Color(0xFF000000),
       huddleControlSurface: const Color(0xFF333333),
       onHuddleDrawer: const Color(0xFFFAFAFA),
@@ -64,6 +65,7 @@ class AppTheme {
       success: const Color(0xFF3DD68C), // Desktop green-11
       warning: const Color(0xFFFFCA16), // Desktop amber-11
       accent: scheme.tertiary,
+      unread: const Color(0xFFF4BCCF), // Desktop status-unread (magenta-11)
       huddleDrawerSurface: scheme.primaryContainer,
       huddleControlSurface: Color.alphaBlend(
         scheme.onPrimaryContainer.withValues(alpha: 0.18),

mobile/test/features/activity/activity_page_test.dart

@@ -129,6 +129,7 @@ void main() {
   };
 
   Future<Widget> buildTestable({
+    Brightness brightness = Brightness.light,
     HomeFeedResponse? feed,
     ActivityNotifier Function()? activityNotifier,
     Map<String, UserProfile>? users,
@@ -171,7 +172,9 @@ void main() {
         ...overrides,
       ],
       child: MaterialApp(
-        theme: AppTheme.light(),
+        theme: brightness == Brightness.dark
+            ? AppTheme.dark()
+            : AppTheme.light(),
         builder: (context, child) => MediaQuery(
           data: MediaQuery.of(
             context,
@@ -1002,17 +1005,28 @@ void main() {
   });
 
   testWidgets('unread rows show a dot; read rows do not', (tester) async {
-    await tester.pumpWidget(
-      await buildTestable(
-        // ch1 fully read; ch2 (thread) unread.
-        readContexts: {'ch1': now},
-      ),
-    );
-    await tester.pumpAndSettle();
+    for (final brightness in Brightness.values) {
+      await tester.pumpWidget(
+        await buildTestable(
+          brightness: brightness,
+          // ch1 fully read; ch2 (thread) unread.
+          readContexts: {'ch1': now},
+        ),
+      );
+      await tester.pumpAndSettle();
 
-    expect(find.byKey(const ValueKey('inbox-unread-dot-m1')), findsNothing);
-    expect(find.byKey(const ValueKey('inbox-unread-dot-ag1')), findsNothing);
-    expect(find.byKey(const ValueKey('inbox-unread-dot-a1')), findsOneWidget);
+      expect(find.byKey(const ValueKey('inbox-unread-dot-m1')), findsNothing);
+      expect(find.byKey(const ValueKey('inbox-unread-dot-ag1')), findsNothing);
+      final dot = tester.widget<Container>(
+        find.byKey(const ValueKey('inbox-unread-dot-a1')),
+      );
+      expect(
+        (dot.decoration as BoxDecoration).color,
+        brightness == Brightness.dark
+            ? const Color(0xFFF4BCCF)
+            : const Color(0xFFDF1E85),
+      );
+    }
   });
 
   testWidgets(

mobile/test/features/channels/channels_page_test.dart

@@ -3627,7 +3627,10 @@ void main() {
     );
   });
 
-  for (final viaMenu in [false, true]) {
+  for (final (viaMenu, brightness) in [
+    (false, Brightness.light),
+    (true, Brightness.dark),
+  ]) {
     testWidgets('dots, not bolds, channels with only unread thread replies '
         '(cleared ${viaMenu ? 'by Mark read' : 'by reading the thread'})', (
       tester,
@@ -3661,6 +3664,7 @@ void main() {
 
       await tester.pumpWidget(
         buildTestable(
+          brightness: brightness,
           overrides: [
             channelsProvider.overrideWith(
               () => _FakeNotifier(
@@ -3697,6 +3701,15 @@ void main() {
         find.byKey(const ValueKey('channel-attention-dot-1')),
         findsOneWidget,
       );
+      final dot = tester.widget<Container>(
+        find.byKey(const ValueKey('channel-attention-dot-1')),
+      );
+      expect(
+        (dot.decoration as BoxDecoration).color,
+        brightness == Brightness.dark
+            ? const Color(0xFFF4BCCF)
+            : const Color(0xFFDF1E85),
+      );
       expect(
         find.bySemanticsLabel(RegExp(r'general[\s\S]*Needs your attention')),
         findsOneWidget,

mobile/test/shared/theme/app_theme_test.dart

@@ -4,6 +4,17 @@ import 'package:buzz/shared/theme/app_colors.dart';
 import 'package:buzz/shared/theme/app_theme.dart';
 
 void main() {
+  test('unread dots contrast with the list surface in both modes', () {
+    for (final theme in [AppTheme.light(), AppTheme.dark()]) {
+      final dot = theme.extension<AppColors>()!.unread.computeLuminance();
+      final surface = theme.colorScheme.surface.computeLuminance();
+      final contrast = dot > surface
+          ? (dot + .05) / (surface + .05)
+          : (surface + .05) / (dot + .05);
+      expect(contrast, greaterThanOrEqualTo(3), reason: '${theme.brightness}');
+    }
+  });
+
   test('disables Material touch ripples in every app theme', () {
     expect(AppTheme.light().splashFactory, NoSplash.splashFactory);
     expect(AppTheme.dark().splashFactory, NoSplash.splashFactory);