Preserve agent activity across thread scopes

Signed-off-by: kenny lopez <klopez4212@gmail.com>

mobile/lib/features/channels/agent_activity/working_bots_provider.dart

@@ -155,17 +155,28 @@ final composerActivityStateProvider = Provider.autoDispose
 /// Agent pubkeys working in a channel, for the members badge and sheet.
 final workingBotPubkeysProvider = Provider.autoDispose
     .family<Set<String>, String>((ref, channelId) {
-      final activity = ref.watch(
-        composerActivityStateProvider((
-          channelId: channelId,
-          threadHeadId: null,
-        )),
-      );
-      return Set.unmodifiable(
-        activity.agents
-            .where((agent) => agent.isWorking)
-            .map((agent) => agent.pubkey),
-      );
+      final threadScopes = <String?>{
+        null,
+        for (final entry in ref.watch(channelTypingProvider(channelId)))
+          entry.threadHeadId,
+        for (final turn in ref.watch(composerAgentTurnStatesProvider))
+          if (turn.channelId == channelId) turn.threadHeadId,
+      };
+      final working = <String>{};
+      for (final threadHeadId in threadScopes) {
+        final activity = ref.watch(
+          composerActivityStateProvider((
+            channelId: channelId,
+            threadHeadId: threadHeadId,
+          )),
+        );
+        working.addAll(
+          activity.agents
+              .where((agent) => agent.isWorking)
+              .map((agent) => agent.pubkey),
+        );
+      }
+      return Set.unmodifiable(working);
     });
 
 int _compareComposerTurnRecency(AgentTurnState a, AgentTurnState b) {

mobile/lib/features/channels/thread_detail_page.dart

@@ -724,7 +724,7 @@ class ThreadDetailPage extends HookConsumerWidget {
               if (!isMember || isArchived)
                 _ThreadTypingIndicator(
                   channelId: channelId,
-                  threadHeadId: threadHead.id,
+                  threadHeadId: effectiveRootId,
                   animated: false,
                   overlayTopBoundary: frostedAppBarHeight(context),
                 ),
@@ -751,7 +751,7 @@ class ThreadDetailPage extends HookConsumerWidget {
                               restoreComposerFocus,
                             ) => _ThreadTypingIndicator(
                               channelId: channelId,
-                              threadHeadId: threadHead.id,
+                              threadHeadId: effectiveRootId,
                               horizontalInset: 0,
                               overlayTopBoundary: frostedAppBarHeight(context),
                               compactWidthFactor: 0.85,

mobile/test/features/channels/agent_activity/working_bots_provider_test.dart

@@ -259,6 +259,52 @@ void main() {
     expect(container.read(workingBotPubkeysProvider(_channelId)), isEmpty);
   });
 
+  test('channel working set includes agents from every thread scope', () {
+    final container = ProviderContainer(
+      overrides: [
+        currentPubkeyProvider.overrideWith((ref) => 'owner'),
+        channelMembersProvider(
+          _channelId,
+        ).overrideWith((ref) async => const <ChannelMember>[]),
+        channelTypingProvider(_channelId).overrideWith(
+          () => _FakeTypingNotifier(const [
+            TypingEntry(
+              pubkey: 'agent-a',
+              threadHeadId: 'thread-1',
+              expiresAtMs: 9999999999999,
+            ),
+            TypingEntry(
+              pubkey: 'human',
+              threadHeadId: 'thread-3',
+              expiresAtMs: 9999999999999,
+            ),
+          ]),
+        ),
+        agentMentionPubkeysProvider(
+          _channelId,
+        ).overrideWith((ref) => const {'agent-a', 'agent-b'}),
+        agentOwnersProvider.overrideWithValue(
+          const AsyncData({'agent-a': 'owner', 'agent-b': 'owner'}),
+        ),
+        userCacheProvider.overrideWith(_FakeUserCacheNotifier.new),
+        observerRelayProvider.overrideWith(
+          () => _FakeObserverRelayNotifier({
+            'agent-b': [_observerFrame('agent-b')],
+          }),
+        ),
+        composerAgentTurnStatesProvider.overrideWithValue([
+          _turn('agent-b', threadHeadId: 'thread-2'),
+        ]),
+      ],
+    );
+    addTearDown(container.dispose);
+
+    expect(container.read(workingBotPubkeysProvider(_channelId)), {
+      'agent-a',
+      'agent-b',
+    });
+  });
+
   test('prefers live work over retained terminal history', () {
     final receiptAt = DateTime.utc(2026, 8, 16, 12, 0, 5);
     final container = ProviderContainer(

mobile/test/features/channels/channel_detail_page_test.dart

@@ -14,6 +14,7 @@ import 'package:lucide_icons_flutter/lucide_icons.dart';
 import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';
 import 'package:buzz/features/channels/channel.dart';
 import 'package:buzz/features/channels/agent_activity/active_agent_turns.dart';
+import 'package:buzz/features/channels/agent_activity/composer_agent_activity_indicator.dart';
 import 'package:buzz/features/channels/agent_activity/observer_models.dart';
 import 'package:buzz/features/channels/agent_activity/observer_subscription.dart';
 import 'package:buzz/features/channels/agent_activity/working_bots_provider.dart';
@@ -4561,6 +4562,11 @@ void main() {
       expect(threadPage.threadHead.id, 'parent');
       expect(threadPage.initialMessageId, 'target');
 
+      final activityIndicator = tester.widget<ComposerAgentActivityIndicator>(
+        find.byType(ComposerAgentActivityIndicator),
+      );
+      expect(activityIndicator.threadHeadId, 'root');
+
       final highlighted = tester.widget<DecoratedBox>(
         find.byKey(const ValueKey('thread-message-target')),
       );