feat: import Chinese-localized Buzz source snapshot

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

mobile/lib/features/forum/forum_models.dart

@@ -0,0 +1,269 @@
+import 'package:flutter/foundation.dart';
+
+import '../../l10n/app_localizations.dart';
+import '../../shared/relay/relay.dart';
+
+/// A top-level forum post with an optional thread summary.
+@immutable
+class ForumPost {
+  final String eventId;
+  final String pubkey;
+  final String content;
+  final int kind;
+  final int createdAt;
+  final String channelId;
+  final List<List<String>> tags;
+  final ForumThreadSummary? threadSummary;
+
+  const ForumPost({
+    required this.eventId,
+    required this.pubkey,
+    required this.content,
+    required this.kind,
+    required this.createdAt,
+    required this.channelId,
+    required this.tags,
+    this.threadSummary,
+  });
+
+  factory ForumPost.fromJson(Map<String, dynamic> json) {
+    final rawSummary = json['thread_summary'] as Map<String, dynamic>?;
+    return ForumPost(
+      eventId: json['event_id'] as String,
+      pubkey: json['pubkey'] as String,
+      content: json['content'] as String,
+      kind: json['kind'] as int,
+      createdAt: json['created_at'] as int,
+      channelId: json['channel_id'] as String,
+      tags: (json['tags'] as List<dynamic>)
+          .map((t) => (t as List<dynamic>).map((e) => e as String).toList())
+          .toList(),
+      threadSummary: rawSummary != null
+          ? ForumThreadSummary.fromJson(rawSummary)
+          : null,
+    );
+  }
+
+  /// Build a [ForumPost] from a raw Nostr event (kind:45001).
+  factory ForumPost.fromEvent(NostrEvent event) {
+    return ForumPost(
+      eventId: event.id,
+      pubkey: event.pubkey,
+      content: event.content,
+      kind: event.kind,
+      createdAt: event.createdAt,
+      channelId: event.channelId ?? '',
+      tags: event.tags,
+    );
+  }
+
+  /// Extract mention pubkeys from p-tags.
+  List<String> get mentionPubkeys => [
+    for (final tag in tags)
+      if (tag.length >= 2 && tag[0] == 'p') tag[1],
+  ];
+}
+
+/// Summary of replies on a forum post.
+@immutable
+class ForumThreadSummary {
+  final int replyCount;
+  final int descendantCount;
+  final int? lastReplyAt;
+  final List<String> participants;
+
+  const ForumThreadSummary({
+    required this.replyCount,
+    required this.descendantCount,
+    this.lastReplyAt,
+    required this.participants,
+  });
+
+  factory ForumThreadSummary.fromJson(Map<String, dynamic> json) {
+    return ForumThreadSummary(
+      replyCount: json['reply_count'] as int? ?? 0,
+      descendantCount: json['descendant_count'] as int? ?? 0,
+      lastReplyAt: json['last_reply_at'] as int?,
+      participants:
+          (json['participants'] as List<dynamic>?)
+              ?.map((e) => e as String)
+              .toList() ??
+          const [],
+    );
+  }
+}
+
+/// A reply within a forum thread.
+@immutable
+class ThreadReply {
+  final String eventId;
+  final String pubkey;
+  final String content;
+  final int kind;
+  final int createdAt;
+  final String channelId;
+  final List<List<String>> tags;
+  final String? parentEventId;
+  final String? rootEventId;
+  final int depth;
+
+  const ThreadReply({
+    required this.eventId,
+    required this.pubkey,
+    required this.content,
+    required this.kind,
+    required this.createdAt,
+    required this.channelId,
+    required this.tags,
+    this.parentEventId,
+    this.rootEventId,
+    required this.depth,
+  });
+
+  factory ThreadReply.fromJson(Map<String, dynamic> json) {
+    return ThreadReply(
+      eventId: json['event_id'] as String,
+      pubkey: json['pubkey'] as String,
+      content: json['content'] as String,
+      kind: json['kind'] as int,
+      createdAt: json['created_at'] as int,
+      channelId: json['channel_id'] as String,
+      tags: (json['tags'] as List<dynamic>)
+          .map((t) => (t as List<dynamic>).map((e) => e as String).toList())
+          .toList(),
+      parentEventId: json['parent_event_id'] as String?,
+      rootEventId: json['root_event_id'] as String?,
+      depth: json['depth'] as int? ?? 0,
+    );
+  }
+
+  /// Build a [ThreadReply] from a raw Nostr event.
+  factory ThreadReply.fromEvent(NostrEvent event) {
+    final ref = event.threadReference;
+    return ThreadReply(
+      eventId: event.id,
+      pubkey: event.pubkey,
+      content: event.content,
+      kind: event.kind,
+      createdAt: event.createdAt,
+      channelId: event.channelId ?? '',
+      tags: event.tags,
+      parentEventId: ref.parentId,
+      rootEventId: ref.rootId,
+      depth: 0,
+    );
+  }
+
+  /// Extract mention pubkeys from p-tags.
+  List<String> get mentionPubkeys => [
+    for (final tag in tags)
+      if (tag.length >= 2 && tag[0] == 'p') tag[1],
+  ];
+}
+
+/// Paginated response for forum posts.
+@immutable
+class ForumPostsResponse {
+  final List<ForumPost> posts;
+  final int? nextCursor;
+
+  const ForumPostsResponse({required this.posts, this.nextCursor});
+
+  factory ForumPostsResponse.fromJson(Map<String, dynamic> json) {
+    final messages = json['messages'] as List<dynamic>? ?? const [];
+    return ForumPostsResponse(
+      posts: messages
+          .cast<Map<String, dynamic>>()
+          .map(ForumPost.fromJson)
+          .toList(),
+      nextCursor: json['next_cursor'] as int?,
+    );
+  }
+
+  /// Build from a list of kind:45001 events. Posts are sorted newest-first.
+  factory ForumPostsResponse.fromEvents(List<NostrEvent> events) {
+    final posts = events.map(ForumPost.fromEvent).toList()
+      ..sort((a, b) => b.createdAt.compareTo(a.createdAt));
+    return ForumPostsResponse(posts: posts, nextCursor: null);
+  }
+}
+
+/// Response for a single forum thread with replies.
+@immutable
+class ForumThreadResponse {
+  final ForumPost post;
+  final List<ThreadReply> replies;
+  final int totalReplies;
+  final String? nextCursor;
+
+  const ForumThreadResponse({
+    required this.post,
+    required this.replies,
+    required this.totalReplies,
+    this.nextCursor,
+  });
+
+  factory ForumThreadResponse.fromJson(Map<String, dynamic> json) {
+    final repliesJson = json['replies'] as List<dynamic>? ?? const [];
+    return ForumThreadResponse(
+      post: ForumPost.fromJson(json['root'] as Map<String, dynamic>),
+      replies: repliesJson
+          .cast<Map<String, dynamic>>()
+          .map(ThreadReply.fromJson)
+          .toList(),
+      totalReplies: json['total_replies'] as int? ?? 0,
+      nextCursor: json['next_cursor'] as String?,
+    );
+  }
+
+  /// Build from a root event and a list of reply events. Replies are sorted
+  /// oldest-first so the UI can render them top-down.
+  factory ForumThreadResponse.fromEvents({
+    required NostrEvent root,
+    required List<NostrEvent> replies,
+  }) {
+    final sortedReplies = replies.map(ThreadReply.fromEvent).toList()
+      ..sort((a, b) => a.createdAt.compareTo(b.createdAt));
+    return ForumThreadResponse(
+      post: ForumPost.fromEvent(root),
+      replies: sortedReplies,
+      totalReplies: sortedReplies.length,
+      nextCursor: null,
+    );
+  }
+}
+
+/// Format a unix timestamp as a relative time string (e.g. "2h ago").
+String formatRelativeTime(int timestamp) {
+  final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+  final diff = now - timestamp;
+
+  if (diff < 60) return 'just now';
+  if (diff < 3600) return '${diff ~/ 60}m ago';
+  if (diff < 86400) return '${diff ~/ 3600}h ago';
+  if (diff < 604800) return '${diff ~/ 86400}d ago';
+
+  final dt = DateTime.fromMillisecondsSinceEpoch(
+    timestamp * 1000,
+    isUtc: true,
+  ).toLocal();
+  return '${dt.month}/${dt.day}/${dt.year}';
+}
+
+/// Localized variant used by forum UI; the legacy formatter remains for
+/// model-only callers and stable tests.
+String formatRelativeTimeLocalized(AppLocalizations l10n, int timestamp) {
+  final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+  final diff = now - timestamp;
+
+  if (diff < 60) return l10n.forumTimeJustNow;
+  if (diff < 3600) return l10n.forumTimeMinutesAgo(diff ~/ 60);
+  if (diff < 86400) return l10n.forumTimeHoursAgo(diff ~/ 3600);
+  if (diff < 604800) return l10n.forumTimeDaysAgo(diff ~/ 86400);
+
+  final dt = DateTime.fromMillisecondsSinceEpoch(
+    timestamp * 1000,
+    isUtc: true,
+  ).toLocal();
+  return l10n.forumFullDate(dt.month, dt.day, dt.year);
+}

mobile/lib/features/forum/forum_post_card.dart

@@ -0,0 +1,361 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.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/mentions/agent_identity_provider.dart';
+import '../../shared/l10n/l10n.dart';
+import '../../shared/theme/theme.dart';
+import '../../shared/widgets/avatar_image.dart';
+import '../../shared/widgets/modal_presentation.dart';
+import '../channels/message_content.dart';
+import '../profile/user_cache_provider.dart';
+import '../profile/user_profile_sheet.dart';
+import '../profile/user_profile.dart';
+import 'forum_models.dart';
+
+/// Card displaying a forum post preview in the posts list.
+///
+/// Long-press opens an action sheet (copy, delete) matching the stream
+/// message pattern from channel_detail_page.dart.
+class ForumPostCard extends HookConsumerWidget {
+  final ForumPost post;
+  final String? currentPubkey;
+  final VoidCallback onTap;
+  final void Function(String eventId)? onDelete;
+
+  const ForumPostCard({
+    super.key,
+    required this.post,
+    required this.currentPubkey,
+    required this.onTap,
+    this.onDelete,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final mentionPubkeys = useMemoized(
+      () =>
+          post.mentionPubkeys.map((pubkey) => pubkey.toLowerCase()).toSet()
+            ..remove(post.pubkey.toLowerCase()),
+      [post],
+    );
+    final mentionPubkeysKey = (mentionPubkeys.toList()..sort()).join('\u0000');
+
+    useEffect(() {
+      if (mentionPubkeys.isNotEmpty) {
+        ref.read(userCacheProvider.notifier).preload(mentionPubkeys.toList());
+      }
+      return null;
+    }, [mentionPubkeysKey]);
+
+    final pk = post.pubkey.toLowerCase();
+    final profile =
+        ref.watch(userCacheProvider.select((cache) => cache[pk])) ??
+        ref.read(userCacheProvider.notifier).get(pk);
+    final displayName = profile?.label ?? _shortPubkey(post.pubkey);
+    final profileMentionNames = ref.watch(
+      userCacheProvider.select(
+        (cache) => _buildMentionNames(post.mentionPubkeys, cache),
+      ),
+    );
+    final profileOwnedMentionPubkeys = ref.watch(
+      userCacheProvider.select(
+        (cache) =>
+            (post.mentionPubkeys
+                    .where(
+                      (pubkey) =>
+                          cache[pubkey.toLowerCase()]?.ownerPubkey != null,
+                    )
+                    .map((pubkey) => pubkey.toLowerCase())
+                    .toList()
+                  ..sort())
+                .join('\u0000'),
+      ),
+    );
+    final agentMentionPubkeys = agentPubkeysWithProfileOwners(
+      knownAgentPubkeys: ref.watch(agentMentionPubkeysProvider(post.channelId)),
+      profileOwnedAgentPubkeys: profileOwnedMentionPubkeys.isEmpty
+          ? const <String>[]
+          : profileOwnedMentionPubkeys.split('\u0000'),
+    );
+    final mentionNames = mentionNamesWithDirectoryLabels(
+      mentionPubkeys: post.mentionPubkeys,
+      profileMentionNames: profileMentionNames,
+      directoryDisplayNames: ref.watch(agentDirectoryDisplayNamesProvider),
+      agentMentionPubkeys: agentMentionPubkeys,
+    );
+    final preview = post.content.length > 200
+        ? '${post.content.substring(0, 200)}...'
+        : post.content;
+    final summary = post.threadSummary;
+
+    return GestureDetector(
+      onTap: onTap,
+      onLongPress: () => _showActions(context),
+      child: Container(
+        width: double.infinity,
+        padding: const EdgeInsets.all(Grid.twelve),
+        decoration: BoxDecoration(
+          color: context.colors.surfaceContainerHighest,
+          borderRadius: BorderRadius.circular(Radii.lg),
+          border: Border.all(
+            color: context.colors.outlineVariant.withValues(alpha: 0.5),
+          ),
+        ),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // Author row
+            Row(
+              children: [
+                GestureDetector(
+                  behavior: HitTestBehavior.opaque,
+                  onTap: () => showUserProfileSheet(context, post.pubkey),
+                  child: _PostAvatar(profile: profile, pubkey: post.pubkey),
+                ),
+                const SizedBox(width: Grid.xxs),
+                Expanded(
+                  child: GestureDetector(
+                    behavior: HitTestBehavior.opaque,
+                    onTap: () => showUserProfileSheet(context, post.pubkey),
+                    child: Text(
+                      displayName,
+                      maxLines: 1,
+                      style: messageUsernameTextStyle,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                  ),
+                ),
+                const SizedBox(width: Grid.xxs),
+                ConstrainedBox(
+                  constraints: const BoxConstraints(maxWidth: Grid.xxl),
+                  child: Text(
+                    formatRelativeTimeLocalized(
+                      context.l10n,
+                      post.createdAt,
+                    ),
+                    maxLines: 1,
+                    overflow: TextOverflow.ellipsis,
+                    style: messageTimestampTextStyle.copyWith(
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                  ),
+                ),
+                const SizedBox(width: Grid.half),
+                SizedBox(
+                  width: 24,
+                  height: 24,
+                  child: IconButton(
+                    onPressed: () => _showActions(context),
+                    icon: Icon(
+                      LucideIcons.ellipsis,
+                      size: 16,
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                    padding: EdgeInsets.zero,
+                    visualDensity: VisualDensity.compact,
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: Grid.xxs),
+
+            ShaderMask(
+              shaderCallback: (bounds) => const LinearGradient(
+                begin: Alignment.topCenter,
+                end: Alignment.bottomCenter,
+                colors: [Colors.white, Colors.white, Colors.transparent],
+                stops: [0.0, 0.75, 1.0],
+              ).createShader(bounds),
+              blendMode: BlendMode.dstIn,
+              child: ConstrainedBox(
+                constraints: const BoxConstraints(maxHeight: 120),
+                child: IgnorePointer(
+                  child: MessageContent(
+                    content: preview,
+                    mentionNames: mentionNames,
+                    agentMentionPubkeys: agentMentionPubkeys,
+                    tags: post.tags,
+                    baseStyle: messageBodyTextStyle.copyWith(
+                      color: context.colors.onSurface,
+                    ),
+                  ),
+                ),
+              ),
+            ),
+
+            // Thread summary
+            if (summary != null && summary.replyCount > 0) ...[
+              const SizedBox(height: Grid.xxs),
+              Row(
+                children: [
+                  Icon(
+                    LucideIcons.messageSquare,
+                    size: 14,
+                    color: context.colors.onSurfaceVariant,
+                  ),
+                  const SizedBox(width: Grid.half),
+                  Text(
+                    context.l10n.replyCount(summary.replyCount),
+                    style: context.textTheme.labelSmall?.copyWith(
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                  ),
+                  if (summary.lastReplyAt != null) ...[
+                    const SizedBox(width: Grid.half),
+                    Text(
+                      '\u00b7',
+                      style: context.textTheme.labelSmall?.copyWith(
+                        color: context.colors.onSurfaceVariant.withValues(
+                          alpha: 0.5,
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: Grid.half),
+                    Text(
+                      context.l10n.lastReply(
+                        formatRelativeTimeLocalized(
+                          context.l10n,
+                          summary.lastReplyAt!,
+                        ),
+                      ),
+                      style: context.textTheme.labelSmall?.copyWith(
+                        color: context.colors.onSurfaceVariant,
+                      ),
+                    ),
+                  ],
+                ],
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+
+  void _showActions(BuildContext context) {
+    final isOwn =
+        currentPubkey != null &&
+        post.pubkey.toLowerCase() == currentPubkey!.toLowerCase();
+
+    showBuzzModalBottomSheet<void>(
+      context: context,
+      showDragHandle: true,
+      builder: (sheetContext) => SafeArea(
+        child: IconTheme.merge(
+          data: const IconThemeData(size: 22),
+          child: Padding(
+            padding: const EdgeInsets.fromLTRB(
+              Grid.gutter,
+              0,
+              Grid.gutter,
+              Grid.xs,
+            ),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                ListTile(
+                  leading: const Icon(LucideIcons.copy),
+                  title: Text(context.l10n.copyText),
+                  onTap: () {
+                    Navigator.of(sheetContext).pop();
+                    Clipboard.setData(ClipboardData(text: post.content));
+                  },
+                ),
+                if (isOwn && onDelete != null)
+                  ListTile(
+                    leading: Icon(
+                      LucideIcons.trash2,
+                      color: sheetContext.colors.error,
+                    ),
+                    title: Text(
+                      context.l10n.deletePost,
+                      style: TextStyle(color: sheetContext.colors.error),
+                    ),
+                    onTap: () {
+                      Navigator.of(sheetContext).pop();
+                      _confirmDelete(context);
+                    },
+                  ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  void _confirmDelete(BuildContext context) {
+    showBuzzDialog<void>(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: Text(context.l10n.deletePost),
+        content: Text(context.l10n.cannotUndo),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text(context.l10n.cancel),
+          ),
+          FilledButton(
+            onPressed: () {
+              Navigator.of(dialogContext).pop();
+              onDelete?.call(post.eventId);
+            },
+            style: FilledButton.styleFrom(
+              backgroundColor: dialogContext.colors.error,
+            ),
+            child: Text(context.l10n.delete),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _PostAvatar extends StatelessWidget {
+  final UserProfile? profile;
+  final String pubkey;
+
+  const _PostAvatar({required this.profile, required this.pubkey});
+
+  @override
+  Widget build(BuildContext context) {
+    final initial =
+        profile?.initial ?? (pubkey.isNotEmpty ? pubkey[0].toUpperCase() : '?');
+    final avatarUrl = profile?.avatarUrl;
+
+    return AvatarImage(
+      imageUrl: avatarUrl,
+      radius: 14,
+      backgroundColor: context.colors.primaryContainer,
+      fallback: Text(
+        initial,
+        style: context.textTheme.labelSmall?.copyWith(
+          color: context.colors.onPrimaryContainer,
+          fontWeight: FontWeight.w600,
+        ),
+      ),
+    );
+  }
+}
+
+String _shortPubkey(String pubkey) {
+  if (pubkey.length > 12) return '${pubkey.substring(0, 8)}\u2026';
+  return pubkey;
+}
+
+Map<String, String> _buildMentionNames(
+  List<String> mentionPubkeys,
+  Map<String, UserProfile> userCache,
+) {
+  final names = <String, String>{};
+  for (final pk in mentionPubkeys) {
+    final p = userCache[pk.toLowerCase()];
+    if (p?.displayName != null) {
+      names[pk.toLowerCase()] = p!.displayName!;
+    }
+  }
+  return names;
+}

mobile/lib/features/forum/forum_posts_view.dart

@@ -0,0 +1,227 @@
+import 'dart:async';
+
+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 '../../shared/widgets/frosted_app_bar.dart';
+import '../../shared/widgets/bee_refresh_indicator.dart';
+import '../channels/channel.dart';
+import '../channels/compose_bar.dart';
+import 'forum_models.dart';
+import 'forum_post_card.dart';
+import 'forum_provider.dart';
+import 'forum_thread_page.dart';
+
+/// Main forum view — replaces the old _ForumPlaceholder.
+///
+/// Shows a list of forum posts for the channel with a FAB to open the compose
+/// bar, and navigates to [ForumThreadPage] when a post is tapped.
+class ForumPostsView extends HookConsumerWidget {
+  final Channel channel;
+  final String? currentPubkey;
+
+  const ForumPostsView({
+    super.key,
+    required this.channel,
+    required this.currentPubkey,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final postsAsync = ref.watch(forumPostsProvider(channel.id));
+    final isComposing = useState(false);
+    // A queued attachment can finish after this view is popped. Capture the
+    // app-level provider container instead of retaining the route's WidgetRef.
+    final providerContainer = ProviderScope.containerOf(context, listen: false);
+    final forumDelivery = ForumEventDelivery.capture(providerContainer);
+
+    // Periodic refresh (every 15s, matching desktop).
+    useEffect(() {
+      final timer = Stream.periodic(const Duration(seconds: 15)).listen((_) {
+        ref.invalidate(forumPostsProvider(channel.id));
+      });
+      return timer.cancel;
+    }, [channel.id]);
+
+    final canPost = channel.isMember && !channel.isArchived;
+
+    return Column(
+      children: [
+        Expanded(
+          child: Scaffold(
+            // Transparent so the parent Scaffold's background shows through.
+            backgroundColor: Colors.transparent,
+            floatingActionButton: canPost && !isComposing.value
+                ? FloatingActionButton(
+                    heroTag: 'forum-fab',
+                    onPressed: () => isComposing.value = true,
+                    tooltip: context.l10n.newPost,
+                    shape: const CircleBorder(),
+                    child: const Icon(LucideIcons.plus),
+                  )
+                : null,
+            body: postsAsync.when(
+              loading: () => Padding(
+                padding: EdgeInsets.only(top: frostedAppBarHeight(context)),
+                child: const Center(
+                  child: BuzzLoadingIndicator(
+                    size: 44,
+                    semanticLabel: context.l10n.loadingPosts,
+                  ),
+                ),
+              ),
+              error: (e, _) => Padding(
+                padding: EdgeInsets.only(top: frostedAppBarHeight(context)),
+                child: Center(
+                  child: Text(
+                    context.l10n.failedLoadPosts,
+                    style: context.textTheme.bodyMedium?.copyWith(
+                      color: context.colors.error,
+                    ),
+                  ),
+                ),
+              ),
+              data: (response) {
+                final posts = response.posts;
+                if (posts.isEmpty) {
+                  return _EmptyState(
+                    isMember: channel.isMember,
+                    isArchived: channel.isArchived,
+                  );
+                }
+                return BeeRefreshIndicator(
+                  onRefresh: () async {
+                    ref.invalidate(forumPostsProvider(channel.id));
+                    await ref.read(forumPostsProvider(channel.id).future);
+                  },
+                  child: ListView.separated(
+                    padding: EdgeInsets.only(
+                      top: frostedAppBarHeight(context),
+                      left: Grid.gutter,
+                      right: Grid.gutter,
+                      bottom: Grid.xs,
+                    ),
+                    itemCount: posts.length,
+                    separatorBuilder: (_, _) =>
+                        const SizedBox(height: Grid.xxs),
+                    itemBuilder: (context, index) {
+                      final post = posts[index];
+                      return ForumPostCard(
+                        post: post,
+                        currentPubkey: currentPubkey,
+                        onTap: () => _openThread(context, post),
+                        onDelete: (eventId) async {
+                          await deleteForumEvent(
+                            ref,
+                            channelId: channel.id,
+                            eventId: eventId,
+                          );
+                        },
+                      );
+                    },
+                  ),
+                );
+              },
+            ),
+          ),
+        ),
+        if (isComposing.value) ...[
+          Align(
+            alignment: Alignment.centerRight,
+            child: Padding(
+              padding: const EdgeInsets.only(right: Grid.xxs),
+              child: IconButton(
+                onPressed: () => isComposing.value = false,
+                icon: const Icon(LucideIcons.x, size: 18),
+                tooltip: context.l10n.dismiss,
+                visualDensity: VisualDensity.compact,
+              ),
+            ),
+          ),
+          ComposeBar(
+            channelId: channel.id,
+            hintText: context.l10n.writePostHint,
+            onSend:
+                (
+                  content,
+                  mentionPubkeys, {
+                  mediaTags = const <List<String>>[],
+                }) async {
+                  await forumDelivery.createPost(
+                    channelId: channel.id,
+                    content: content,
+                    mentionPubkeys: mentionPubkeys,
+                    mediaTags: mediaTags,
+                  );
+                  if (context.mounted) isComposing.value = false;
+                },
+          ),
+        ],
+      ],
+    );
+  }
+
+  void _openThread(BuildContext context, ForumPost post) {
+    Navigator.of(context).push(
+      MaterialPageRoute<void>(
+        builder: (_) => ForumThreadPage(
+          channelId: channel.id,
+          postEventId: post.eventId,
+          currentPubkey: currentPubkey,
+          isMember: channel.isMember,
+          isArchived: channel.isArchived,
+        ),
+      ),
+    );
+  }
+}
+
+class _EmptyState extends StatelessWidget {
+  final bool isMember;
+  final bool isArchived;
+
+  const _EmptyState({required this.isMember, required this.isArchived});
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.symmetric(horizontal: Grid.sm),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(
+              LucideIcons.messageSquareText,
+              size: Grid.xl,
+              color: context.colors.onSurfaceVariant,
+            ),
+            const SizedBox(height: Grid.xxs),
+            Text(
+              context.l10n.noPostsYet,
+              style: context.textTheme.bodyLarge?.copyWith(
+                color: context.colors.onSurfaceVariant,
+              ),
+            ),
+            const SizedBox(height: Grid.half),
+            Text(
+              isArchived
+                  ? context.l10n.forumArchived
+                  : isMember
+                  ? context.l10n.startForumDiscussion
+                  : context.l10n.joinForumToPost,
+              style: context.textTheme.bodySmall?.copyWith(
+                color: context.colors.onSurfaceVariant,
+              ),
+              textAlign: TextAlign.center,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

mobile/lib/features/forum/forum_provider.dart

@@ -0,0 +1,189 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import '../../shared/relay/relay.dart';
+import '../channels/channel_management_provider.dart';
+import '../../shared/custom_emoji/custom_emoji.dart';
+import '../../shared/custom_emoji/custom_emoji_provider.dart';
+import 'forum_models.dart';
+
+/// Fetches forum posts (kind:45001) for a channel from the relay.
+///
+/// Posts are top-level events tagged `#h:<channelId>`. Invalidate to refresh
+/// (e.g. after creating a new post).
+final forumPostsProvider = FutureProvider.family<ForumPostsResponse, String>((
+  ref,
+  channelId,
+) async {
+  final session = ref.watch(relaySessionProvider.notifier);
+  final events = await session.fetchHistory(
+    NostrFilters.forumPosts(channelId, limit: 50),
+  );
+  return ForumPostsResponse.fromEvents(events);
+});
+
+/// Fetches a forum thread (root post + replies) from the relay.
+final forumThreadProvider =
+    FutureProvider.family<
+      ForumThreadResponse,
+      ({String channelId, String eventId})
+    >((ref, args) async {
+      final session = ref.watch(relaySessionProvider.notifier);
+
+      final results = await Future.wait([
+        // Root event lookup by id.
+        session.fetchHistory(
+          NostrFilter(
+            kinds: const [9, 40002, 45001, 45003],
+            ids: [args.eventId],
+            limit: 1,
+          ),
+        ),
+        // Replies pointing at this root.
+        session.fetchHistory(
+          NostrFilters.forumThread(args.eventId, args.channelId),
+        ),
+      ]);
+
+      final rootEvents = results[0];
+      final replyEvents = results[1];
+      if (rootEvents.isEmpty) {
+        throw Exception('Forum thread not found: ${args.eventId}');
+      }
+      return ForumThreadResponse.fromEvents(
+        root: rootEvents.first,
+        replies: replyEvents,
+      );
+    });
+
+/// A forum event delivery bound to the community where composition began.
+///
+/// Attachment uploads can outlive their route. Capturing the relay identity,
+/// signing key, and emoji palette prevents a queued draft from being delivered
+/// to a different community after the user switches relays.
+class ForumEventDelivery {
+  final ProviderContainer _container;
+  final String _relayUrl;
+  final String? _nsec;
+  final SignedEventRelay _relay;
+  final List<CustomEmoji> _customEmoji;
+
+  ForumEventDelivery._({
+    required ProviderContainer container,
+    required String relayUrl,
+    required String? nsec,
+    required SignedEventRelay relay,
+    required List<CustomEmoji> customEmoji,
+  }) : _container = container,
+       _relayUrl = relayUrl,
+       _nsec = nsec,
+       _relay = relay,
+       _customEmoji = customEmoji;
+
+  /// Captures the active community dependencies for a future delivery.
+  factory ForumEventDelivery.capture(ProviderContainer container) {
+    final config = container.read(relayConfigProvider);
+    return ForumEventDelivery._(
+      container: container,
+      relayUrl: config.baseUrl,
+      nsec: config.nsec,
+      relay: SignedEventRelay(
+        session: container.read(relaySessionProvider.notifier),
+        nsec: config.nsec,
+      ),
+      customEmoji: List<CustomEmoji>.unmodifiable(
+        container.read(customEmojiListProvider),
+      ),
+    );
+  }
+
+  /// Creates a new forum post (kind:45001).
+  Future<void> createPost({
+    required String channelId,
+    required String content,
+    List<String> mentionPubkeys = const [],
+    List<List<String>> mediaTags = const [],
+  }) async {
+    await _submit(
+      kind: EventKind.forumPost,
+      channelId: channelId,
+      content: content,
+      mentionPubkeys: mentionPubkeys,
+      mediaTags: mediaTags,
+    );
+    _container.invalidate(forumPostsProvider(channelId));
+  }
+
+  /// Creates a reply to a forum post (kind:45003).
+  Future<void> createReply({
+    required String channelId,
+    required String parentEventId,
+    required String content,
+    List<String> mentionPubkeys = const [],
+    List<List<String>> mediaTags = const [],
+  }) async {
+    await _submit(
+      kind: EventKind.forumComment,
+      channelId: channelId,
+      parentEventId: parentEventId,
+      content: content,
+      mentionPubkeys: mentionPubkeys,
+      mediaTags: mediaTags,
+    );
+    _container.invalidate(forumPostsProvider(channelId));
+    _container.invalidate(
+      forumThreadProvider((channelId: channelId, eventId: parentEventId)),
+    );
+  }
+
+  Future<void> _submit({
+    required int kind,
+    required String channelId,
+    required String content,
+    String? parentEventId,
+    required List<String> mentionPubkeys,
+    required List<List<String>> mediaTags,
+  }) async {
+    final currentConfig = _container.read(relayConfigProvider);
+    if (currentConfig.baseUrl != _relayUrl || currentConfig.nsec != _nsec) {
+      throw StateError(
+        'Forum delivery cancelled because the active community changed',
+      );
+    }
+
+    final selfPubkey = _relay.pubkey?.toLowerCase();
+    final seen = <String>{?selfPubkey};
+    final normalizedMentions = [
+      for (final pk in mentionPubkeys)
+        if (seen.add(pk.toLowerCase())) pk,
+    ];
+
+    await _relay.submit(
+      kind: kind,
+      content: content,
+      tags: [
+        ['h', channelId],
+        if (parentEventId != null) ['e', parentEventId, '', 'reply'],
+        for (final pk in normalizedMentions) ['p', pk],
+        ...mediaTags,
+        ...buildCustomEmojiTags(content, _customEmoji),
+      ],
+    );
+  }
+}
+
+/// Deletes a forum post or reply and invalidates relevant caches.
+Future<void> deleteForumEvent(
+  WidgetRef ref, {
+  required String channelId,
+  required String eventId,
+  String? rootEventId,
+}) async {
+  final actions = ref.read(channelActionsProvider);
+  await actions.deleteMessage(channelId: channelId, eventId: eventId);
+  ref.invalidate(forumPostsProvider(channelId));
+  if (rootEventId != null) {
+    ref.invalidate(
+      forumThreadProvider((channelId: channelId, eventId: rootEventId)),
+    );
+  }
+}

mobile/lib/features/forum/forum_thread_page.dart

@@ -0,0 +1,676 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.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/mentions/agent_identity_provider.dart';
+import '../../shared/l10n/l10n.dart';
+import '../../shared/theme/theme.dart';
+import '../../shared/widgets/avatar_image.dart';
+import '../../shared/widgets/buzz_loading_indicator.dart';
+import '../../shared/widgets/frosted_app_bar.dart';
+import '../../shared/widgets/frosted_scaffold.dart';
+import '../../shared/widgets/modal_presentation.dart';
+import '../channels/compose_bar.dart';
+import '../channels/message_content.dart';
+import '../profile/user_cache_provider.dart';
+import '../profile/user_profile.dart';
+import '../profile/user_profile_sheet.dart';
+import 'forum_models.dart';
+import 'forum_provider.dart';
+
+/// Full-screen page showing a forum post and its replies.
+class ForumThreadPage extends HookConsumerWidget {
+  final String channelId;
+  final String postEventId;
+  final String? currentPubkey;
+  final bool isMember;
+  final bool isArchived;
+
+  const ForumThreadPage({
+    super.key,
+    required this.channelId,
+    required this.postEventId,
+    required this.currentPubkey,
+    required this.isMember,
+    required this.isArchived,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final threadAsync = ref.watch(
+      forumThreadProvider((channelId: channelId, eventId: postEventId)),
+    );
+
+    // Periodic refresh (every 10s, matching desktop).
+    useEffect(() {
+      final timer = Stream.periodic(const Duration(seconds: 10)).listen((_) {
+        ref.invalidate(
+          forumThreadProvider((channelId: channelId, eventId: postEventId)),
+        );
+      });
+      return timer.cancel;
+    }, [channelId, postEventId]);
+
+    final isOwnPost =
+        threadAsync
+            .whenData(
+              (t) =>
+                  currentPubkey != null &&
+                  t.post.pubkey.toLowerCase() == currentPubkey!.toLowerCase(),
+            )
+            .value ??
+        false;
+
+    return FrostedScaffold(
+      appBar: FrostedAppBar(
+        title: Text(context.l10n.threadTitle),
+        actions: [
+          if (isOwnPost)
+            IconButton(
+              onPressed: () =>
+                  _showPostActions(context, ref, threadAsync.value!),
+              tooltip: context.l10n.postActions,
+              icon: const Icon(LucideIcons.ellipsis),
+            ),
+        ],
+      ),
+      body: threadAsync.when(
+        loading: () => Padding(
+          padding: EdgeInsets.only(top: frostedAppBarHeight(context)),
+          child: Center(
+            child: BuzzLoadingIndicator(
+              size: 44,
+              semanticLabel: context.l10n.loadingThread,
+            ),
+          ),
+        ),
+        error: (e, _) => Padding(
+          padding: EdgeInsets.only(top: frostedAppBarHeight(context)),
+          child: Center(
+            child: Text(
+              context.l10n.failedLoadThread,
+              style: context.textTheme.bodyMedium?.copyWith(
+                color: context.colors.error,
+              ),
+            ),
+          ),
+        ),
+        data: (thread) => _ThreadContent(
+          thread: thread,
+          channelId: channelId,
+          currentPubkey: currentPubkey,
+          isMember: isMember,
+          isArchived: isArchived,
+        ),
+      ),
+    );
+  }
+
+  void _showPostActions(
+    BuildContext context,
+    WidgetRef ref,
+    ForumThreadResponse thread,
+  ) {
+    showBuzzModalBottomSheet<void>(
+      context: context,
+      showDragHandle: true,
+      builder: (sheetContext) => SafeArea(
+        child: IconTheme.merge(
+          data: const IconThemeData(size: 22),
+          child: Padding(
+            padding: const EdgeInsets.fromLTRB(
+              Grid.gutter,
+              0,
+              Grid.gutter,
+              Grid.xs,
+            ),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                ListTile(
+                  leading: const Icon(LucideIcons.copy),
+                  title: Text(context.l10n.copyText),
+                  onTap: () {
+                    Navigator.of(sheetContext).pop();
+                    Clipboard.setData(ClipboardData(text: thread.post.content));
+                  },
+                ),
+                ListTile(
+                  leading: Icon(
+                    LucideIcons.trash2,
+                    color: sheetContext.colors.error,
+                  ),
+                  title: Text(
+                    context.l10n.deletePost,
+                    style: TextStyle(color: sheetContext.colors.error),
+                  ),
+                  onTap: () {
+                    Navigator.of(sheetContext).pop();
+                    _confirmDeletePost(context, ref, thread.post.eventId);
+                  },
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  void _confirmDeletePost(BuildContext context, WidgetRef ref, String eventId) {
+    showBuzzDialog<void>(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: Text(context.l10n.deletePost),
+        content: Text(context.l10n.cannotUndo),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text(context.l10n.cancel),
+          ),
+          FilledButton(
+            onPressed: () async {
+              Navigator.of(dialogContext).pop();
+              await deleteForumEvent(
+                ref,
+                channelId: channelId,
+                eventId: eventId,
+              );
+              if (context.mounted) {
+                Navigator.of(context).pop();
+              }
+            },
+            style: FilledButton.styleFrom(
+              backgroundColor: dialogContext.colors.error,
+            ),
+            child: Text(context.l10n.delete),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ThreadContent extends HookConsumerWidget {
+  final ForumThreadResponse thread;
+  final String channelId;
+  final String? currentPubkey;
+  final bool isMember;
+  final bool isArchived;
+
+  const _ThreadContent({
+    required this.thread,
+    required this.channelId,
+    required this.currentPubkey,
+    required this.isMember,
+    required this.isArchived,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Background media delivery may outlive this route's WidgetRef.
+    final providerContainer = ProviderScope.containerOf(context, listen: false);
+    final forumDelivery = ForumEventDelivery.capture(providerContainer);
+    final post = thread.post;
+    final replies = thread.replies;
+
+    // Preload profiles for all participants and tagged mentions.
+    final allPubkeys = useMemoized(() {
+      final pks = <String>{
+        post.pubkey.toLowerCase(),
+        ...post.mentionPubkeys.map((pubkey) => pubkey.toLowerCase()),
+      };
+      for (final reply in replies) {
+        pks
+          ..add(reply.pubkey.toLowerCase())
+          ..addAll(reply.mentionPubkeys.map((pubkey) => pubkey.toLowerCase()));
+      }
+      return pks.toList()..sort();
+    }, [post, replies]);
+    final allPubkeysKey = allPubkeys.join('\u0000');
+
+    useEffect(() {
+      if (allPubkeys.isNotEmpty) {
+        ref.read(userCacheProvider.notifier).preload(allPubkeys);
+      }
+      return null;
+    }, [allPubkeysKey]);
+
+    return Column(
+      children: [
+        Expanded(
+          child: ListView(
+            padding: EdgeInsets.only(
+              top: frostedAppBarHeight(context),
+              bottom: Grid.xs,
+            ),
+            children: [
+              _OriginalPost(post: post),
+
+              Padding(
+                padding: const EdgeInsets.symmetric(
+                  horizontal: Grid.gutter,
+                  vertical: Grid.xxs,
+                ),
+                child: Row(
+                  children: [
+                    Icon(
+                      LucideIcons.messageSquare,
+                      size: 16,
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                    const SizedBox(width: Grid.half),
+                    Text(
+                      context.l10n.replyCount(replies.length),
+                      style: context.textTheme.labelMedium?.copyWith(
+                        color: context.colors.onSurfaceVariant,
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+
+              // Reply list
+              if (replies.isEmpty)
+                Padding(
+                  padding: const EdgeInsets.all(Grid.sm),
+                  child: Text(
+                    context.l10n.noRepliesYet,
+                    style: context.textTheme.bodyMedium?.copyWith(
+                      color: context.colors.onSurfaceVariant,
+                    ),
+                    textAlign: TextAlign.center,
+                  ),
+                )
+              else
+                for (final reply in replies)
+                  _ReplyRow(
+                    reply: reply,
+                    currentPubkey: currentPubkey,
+                    channelId: channelId,
+                    rootEventId: post.eventId,
+                  ),
+            ],
+          ),
+        ),
+
+        // Reply composer
+        if (isMember && !isArchived)
+          ComposeBar(
+            channelId: channelId,
+            hintText: context.l10n.replyToPost,
+            onSend:
+                (
+                  content,
+                  mentionPubkeys, {
+                  mediaTags = const <List<String>>[],
+                }) => forumDelivery.createReply(
+                  channelId: channelId,
+                  parentEventId: post.eventId,
+                  content: content,
+                  mentionPubkeys: mentionPubkeys,
+                  mediaTags: mediaTags,
+                ),
+          ),
+      ],
+    );
+  }
+}
+
+class _OriginalPost extends ConsumerWidget {
+  final ForumPost post;
+
+  const _OriginalPost({required this.post});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final pk = post.pubkey.toLowerCase();
+    final profile =
+        ref.watch(userCacheProvider.select((cache) => cache[pk])) ??
+        ref.read(userCacheProvider.notifier).get(pk);
+    final displayName = profile?.label ?? _shortPubkey(post.pubkey);
+
+    final userCache = ref.watch(userCacheProvider);
+    final agentMentionPubkeys = agentPubkeysWithProfileOwners(
+      knownAgentPubkeys: ref.watch(agentMentionPubkeysProvider(post.channelId)),
+      profileOwnedAgentPubkeys: [
+        for (final profile in userCache.values)
+          if (profile.ownerPubkey != null) profile.pubkey,
+      ],
+    );
+    final mentionNames = mentionNamesWithDirectoryLabels(
+      mentionPubkeys: post.mentionPubkeys,
+      profileMentionNames: _buildMentionNames(post.mentionPubkeys, userCache),
+      directoryDisplayNames: ref.watch(agentDirectoryDisplayNamesProvider),
+      agentMentionPubkeys: agentMentionPubkeys,
+    );
+
+    return Padding(
+      padding: const EdgeInsets.all(Grid.xs),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              GestureDetector(
+                onTap: () => showUserProfileSheet(context, post.pubkey),
+                child: _Avatar(
+                  profile: profile,
+                  pubkey: post.pubkey,
+                  radius: 16,
+                ),
+              ),
+              const SizedBox(width: Grid.xxs),
+              Expanded(
+                child: Row(
+                  children: [
+                    Expanded(
+                      child: GestureDetector(
+                        onTap: () => showUserProfileSheet(context, post.pubkey),
+                        child: Text(
+                          displayName,
+                          maxLines: 1,
+                          style: messageUsernameTextStyle,
+                          overflow: TextOverflow.ellipsis,
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: Grid.xxs),
+                    ConstrainedBox(
+                      constraints: const BoxConstraints(maxWidth: Grid.xxl),
+                      child: Text(
+                        formatRelativeTimeLocalized(
+                          context.l10n,
+                          post.createdAt,
+                        ),
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        style: messageTimestampTextStyle.copyWith(
+                          color: context.colors.onSurfaceVariant,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: Grid.xxs),
+          MessageContent(
+            content: post.content,
+            mentionNames: mentionNames,
+            agentMentionPubkeys: agentMentionPubkeys,
+            tags: post.tags,
+            baseStyle: messageBodyTextStyle.copyWith(
+              color: context.colors.onSurface,
+            ),
+            onMentionTap: (pubkey) => showUserProfileSheet(context, pubkey),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _ReplyRow extends ConsumerWidget {
+  final ThreadReply reply;
+  final String? currentPubkey;
+  final String channelId;
+  final String rootEventId;
+
+  const _ReplyRow({
+    required this.reply,
+    required this.currentPubkey,
+    required this.channelId,
+    required this.rootEventId,
+  });
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final pk = reply.pubkey.toLowerCase();
+    final profile =
+        ref.watch(userCacheProvider.select((cache) => cache[pk])) ??
+        ref.read(userCacheProvider.notifier).get(pk);
+    final displayName = profile?.label ?? _shortPubkey(reply.pubkey);
+
+    final userCache = ref.watch(userCacheProvider);
+    final agentMentionPubkeys = agentPubkeysWithProfileOwners(
+      knownAgentPubkeys: ref.watch(agentMentionPubkeysProvider(channelId)),
+      profileOwnedAgentPubkeys: [
+        for (final profile in userCache.values)
+          if (profile.ownerPubkey != null) profile.pubkey,
+      ],
+    );
+    final mentionNames = mentionNamesWithDirectoryLabels(
+      mentionPubkeys: reply.mentionPubkeys,
+      profileMentionNames: _buildMentionNames(reply.mentionPubkeys, userCache),
+      directoryDisplayNames: ref.watch(agentDirectoryDisplayNamesProvider),
+      agentMentionPubkeys: agentMentionPubkeys,
+    );
+
+    return Padding(
+      padding: const EdgeInsets.symmetric(
+        horizontal: Grid.gutter,
+        vertical: Grid.xxs,
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              GestureDetector(
+                onTap: () => showUserProfileSheet(context, reply.pubkey),
+                child: _Avatar(
+                  profile: profile,
+                  pubkey: reply.pubkey,
+                  radius: 12,
+                ),
+              ),
+              const SizedBox(width: Grid.xxs),
+              Expanded(
+                child: Row(
+                  children: [
+                    Expanded(
+                      child: GestureDetector(
+                        onTap: () =>
+                            showUserProfileSheet(context, reply.pubkey),
+                        child: Text(
+                          displayName,
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis,
+                          style: messageUsernameTextStyle,
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: Grid.xxs),
+                    ConstrainedBox(
+                      constraints: const BoxConstraints(maxWidth: Grid.xxl),
+                      child: Text(
+                        formatRelativeTimeLocalized(
+                          context.l10n,
+                          reply.createdAt,
+                        ),
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        style: messageTimestampTextStyle.copyWith(
+                          color: context.colors.onSurfaceVariant,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              SizedBox(
+                width: 28,
+                height: 28,
+                child: IconButton(
+                  onPressed: () => _showActions(context, ref),
+                  icon: Icon(
+                    LucideIcons.ellipsis,
+                    size: 16,
+                    color: context.colors.onSurfaceVariant,
+                  ),
+                  padding: EdgeInsets.zero,
+                  visualDensity: VisualDensity.compact,
+                ),
+              ),
+            ],
+          ),
+          Padding(
+            padding: const EdgeInsets.only(left: 32, top: Grid.half),
+            child: MessageContent(
+              content: reply.content,
+              mentionNames: mentionNames,
+              agentMentionPubkeys: agentMentionPubkeys,
+              tags: reply.tags,
+              baseStyle: messageBodyTextStyle.copyWith(
+                color: context.colors.onSurface,
+              ),
+              onMentionTap: (pubkey) => showUserProfileSheet(context, pubkey),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _showActions(BuildContext context, WidgetRef ref) {
+    final isOwn =
+        currentPubkey != null &&
+        reply.pubkey.toLowerCase() == currentPubkey!.toLowerCase();
+
+    showBuzzModalBottomSheet<void>(
+      context: context,
+      showDragHandle: true,
+      builder: (sheetContext) => SafeArea(
+        child: IconTheme.merge(
+          data: const IconThemeData(size: 22),
+          child: Padding(
+            padding: const EdgeInsets.fromLTRB(
+              Grid.gutter,
+              0,
+              Grid.gutter,
+              Grid.xs,
+            ),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                ListTile(
+                  leading: const Icon(LucideIcons.copy),
+                  title: Text(context.l10n.copyText),
+                  onTap: () {
+                    Navigator.of(sheetContext).pop();
+                    Clipboard.setData(ClipboardData(text: reply.content));
+                  },
+                ),
+                if (isOwn)
+                  ListTile(
+                    leading: Icon(
+                      LucideIcons.trash2,
+                      color: sheetContext.colors.error,
+                    ),
+                    title: Text(
+                      context.l10n.deleteReply,
+                      style: TextStyle(color: sheetContext.colors.error),
+                    ),
+                    onTap: () {
+                      Navigator.of(sheetContext).pop();
+                      _confirmDelete(context, ref);
+                    },
+                  ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  void _confirmDelete(BuildContext context, WidgetRef ref) {
+    showBuzzDialog<void>(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: Text(context.l10n.deleteReply),
+        content: Text(context.l10n.cannotUndo),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text(context.l10n.cancel),
+          ),
+          FilledButton(
+            onPressed: () async {
+              Navigator.of(dialogContext).pop();
+              await deleteForumEvent(
+                ref,
+                channelId: channelId,
+                eventId: reply.eventId,
+                rootEventId: rootEventId,
+              );
+            },
+            style: FilledButton.styleFrom(
+              backgroundColor: dialogContext.colors.error,
+            ),
+            child: Text(context.l10n.delete),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _Avatar extends StatelessWidget {
+  final UserProfile? profile;
+  final String pubkey;
+  final double radius;
+
+  const _Avatar({
+    required this.profile,
+    required this.pubkey,
+    required this.radius,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final initial =
+        profile?.initial ?? (pubkey.isNotEmpty ? pubkey[0].toUpperCase() : '?');
+    final avatarUrl = profile?.avatarUrl;
+
+    return AvatarImage(
+      imageUrl: avatarUrl,
+      radius: radius,
+      backgroundColor: context.colors.primaryContainer,
+      fallback: Text(
+        initial,
+        style: TextStyle(
+          fontSize: radius * 0.75,
+          fontWeight: FontWeight.w600,
+          color: context.colors.onPrimaryContainer,
+        ),
+      ),
+    );
+  }
+}
+
+Map<String, String> _buildMentionNames(
+  List<String> mentionPubkeys,
+  Map<String, UserProfile> userCache,
+) {
+  final names = <String, String>{};
+  for (final pk in mentionPubkeys) {
+    final p = userCache[pk.toLowerCase()];
+    if (p?.displayName != null) {
+      names[pk.toLowerCase()] = p!.displayName!;
+    }
+  }
+  return names;
+}
+
+String _shortPubkey(String pubkey) {
+  if (pubkey.length > 12) return '${pubkey.substring(0, 8)}\u2026';
+  return pubkey;
+}