feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

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

@@ -0,0 +1,272 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_hooks/flutter_hooks.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:lucide_icons_flutter/lucide_icons.dart';
+
+import '../../../shared/l10n/l10n.dart';
+import '../../../shared/theme/theme.dart';
+import '../../../shared/widgets/buzz_loading_indicator.dart';
+import '../../profile/user_cache_provider.dart';
+import '../date_formatters.dart';
+import 'observer_models.dart';
+import 'observer_subscription.dart';
+import 'transcript_item_widget.dart';
+
+/// Full-screen modal bottom sheet showing the live agent activity transcript.
+class AgentActivitySheet extends HookConsumerWidget {
+  final String channelId;
+  final String agentPubkey;
+
+  const AgentActivitySheet({
+    super.key,
+    required this.channelId,
+    required this.agentPubkey,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final observerState = ref.watch(
+      observerSubscriptionProvider((
+        channelId: channelId,
+        agentPubkey: agentPubkey,
+      )),
+    );
+    final transcript = observerState.transcript;
+    final connection = observerState.connection;
+
+    // Resolve bot name.
+    final profile = ref.watch(
+      userCacheProvider.select((cache) => cache[agentPubkey.toLowerCase()]),
+    );
+    final botName = profile?.label ?? shortPubkey(agentPubkey);
+
+    // Auto-scroll to bottom on new items.
+    final sheetControllerRef = useRef<ScrollController?>(null);
+    final previousLength = useRef(0);
+
+    useEffect(() {
+      final sc = sheetControllerRef.value;
+      if (transcript.length > previousLength.value &&
+          sc != null &&
+          sc.hasClients) {
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (sc.hasClients) {
+            sc.animateTo(
+              sc.position.maxScrollExtent,
+              duration: const Duration(milliseconds: 150),
+              curve: Curves.easeOut,
+            );
+          }
+        });
+      }
+      previousLength.value = transcript.length;
+      return null;
+    }, [transcript.length]);
+
+    // Preload the bot profile.
+    useEffect(() {
+      ref.read(userCacheProvider.notifier).preload([agentPubkey]);
+      return null;
+    }, [agentPubkey]);
+
+    return DraggableScrollableSheet(
+      initialChildSize: 0.9,
+      minChildSize: 0.5,
+      maxChildSize: 0.95,
+      expand: false,
+      builder: (context, sheetScrollController) {
+        sheetControllerRef.value = sheetScrollController;
+        final bottomPadding =
+            MediaQuery.viewPaddingOf(context).bottom + Grid.sm;
+        return Column(
+          children: [
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: Grid.gutter),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Row(
+                    children: [
+                      Icon(
+                        LucideIcons.bot,
+                        size: 18,
+                        color: context.colors.onSurface,
+                      ),
+                      const SizedBox(width: Grid.xxs),
+                      Expanded(
+                        child: Text(
+                          botName,
+                          style: context.textTheme.titleMedium?.copyWith(
+                            fontWeight: FontWeight.w600,
+                          ),
+                          overflow: TextOverflow.ellipsis,
+                        ),
+                      ),
+                      _ConnectionBadge(connection: connection),
+                    ],
+                  ),
+                  const SizedBox(height: Grid.half),
+                  Text(
+                    context.l10n.agentLiveActivityHint,
+                    style: context.textTheme.bodySmall?.copyWith(
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                  ),
+                  const SizedBox(height: Grid.xxs),
+                  Divider(color: context.colors.outlineVariant),
+                ],
+              ),
+            ),
+            // Transcript list
+            Expanded(
+              child: transcript.isEmpty
+                  ? Padding(
+                      padding: EdgeInsets.only(bottom: bottomPadding),
+                      child: _EmptyState(
+                        connection: connection,
+                        errorMessage: observerState.errorMessage,
+                      ),
+                    )
+                  : ListView.builder(
+                      controller: sheetScrollController,
+                      padding: EdgeInsets.fromLTRB(
+                        Grid.gutter,
+                        Grid.xxs,
+                        Grid.gutter,
+                        bottomPadding,
+                      ),
+                      itemCount: transcript.length,
+                      itemBuilder: (context, index) {
+                        return TranscriptItemWidget(item: transcript[index]);
+                      },
+                    ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+}
+
+class _EmptyState extends StatelessWidget {
+  final ObserverConnectionState connection;
+  final String? errorMessage;
+
+  const _EmptyState({required this.connection, this.errorMessage});
+
+  @override
+  Widget build(BuildContext context) {
+    if (connection == ObserverConnectionState.error) {
+      final localizedError =
+          Localizations.localeOf(context).languageCode == 'en'
+          ? errorMessage
+          : context.l10n.agentObserverFailed;
+      return Center(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(LucideIcons.circleX, size: 24, color: context.colors.error),
+            const SizedBox(height: Grid.xxs),
+            Text(
+              '${context.l10n.transcriptError}: '
+              '${localizedError ?? context.l10n.agentUnknownError}',
+              style: context.textTheme.bodySmall?.copyWith(
+                color: context.colors.error,
+              ),
+              textAlign: TextAlign.center,
+            ),
+          ],
+        ),
+      );
+    }
+
+    if (connection == ObserverConnectionState.idle) {
+      return Center(
+        child: Text(
+          context.l10n.agentNotConnected,
+          style: context.textTheme.bodySmall?.copyWith(
+            color: context.colors.onSurfaceVariant,
+          ),
+        ),
+      );
+    }
+
+    // connecting or open — show spinner
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          BuzzLoadingIndicator(
+            size: 28,
+            color: context.colors.onSurfaceVariant,
+            semanticLabel: context.l10n.waitingForAgent,
+          ),
+          const SizedBox(height: Grid.xxs),
+          Text(
+            context.l10n.agentWaitingActivity,
+            style: context.textTheme.bodySmall?.copyWith(
+              color: context.colors.onSurfaceVariant,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ConnectionBadge extends StatelessWidget {
+  final ObserverConnectionState connection;
+
+  const _ConnectionBadge({required this.connection});
+
+  @override
+  Widget build(BuildContext context) {
+    final (color, label) = switch (connection) {
+      ObserverConnectionState.idle => (
+        context.colors.onSurfaceVariant,
+        context.l10n.agentConnectionIdle,
+      ),
+      ObserverConnectionState.connecting => (
+        context.appColors.warning,
+        context.l10n.agentConnectionConnecting,
+      ),
+      ObserverConnectionState.open => (
+        context.appColors.success,
+        context.l10n.agentConnectionLive,
+      ),
+      ObserverConnectionState.error => (
+        context.colors.error,
+        context.l10n.agentConnectionError,
+      ),
+    };
+
+    return Container(
+      padding: const EdgeInsets.symmetric(
+        horizontal: Grid.xxs,
+        vertical: Grid.quarter,
+      ),
+      decoration: BoxDecoration(
+        color: color.withValues(alpha: 0.12),
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Container(
+            width: 6,
+            height: 6,
+            decoration: BoxDecoration(color: color, shape: BoxShape.circle),
+          ),
+          const SizedBox(width: Grid.half),
+          Text(
+            label,
+            style: context.textTheme.labelSmall?.copyWith(
+              color: color,
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}