fix(mobile): recognize kind:9005 deletions in timeline

Bring mobile to parity with desktop's kind:9005 handling. Agents
emit kind:9005 deletes via the CLI; without this, mobile keeps
rendering agent-deleted messages until manual refresh.

Two narrow mobile changes:

1. Add EventKind.nip29DeleteEvent (9005) to nostr_models.dart and
   include it in channelEventKinds so the channel subscription and
   history fetch both pick it up.
2. Teach formatTimeline's deletion walker to treat kind:9005 the same
   as kind:5 — collect e-tag targets from both. Tag shape is identical
   between the two builders so the walker is unmodified beyond the
   kind check.

No mobile DM-notification path was found that mirrors desktop's
handleDmEvent → AppShell.handleDmNotification flow, so no DM kind-gating
fix is needed on mobile today.

Tests: timeline_message_test.dart adds a kind:9005 deletion case
mirroring the existing kind:5 test.

Signed-off-by: Taylor Ho <taylorkmho@gmail.com>

Author: Bart

mobile/lib/features/channels/timeline_message.dart

@@ -211,10 +211,14 @@ List<TimelineMessage> formatTimeline(
   List<NostrEvent> events, {
   String? currentPubkey,
 }) {
-  // 1. Collect deletion targets.
+  // 1. Collect deletion targets. Both kind:5 (NIP-09) and kind:9005
+  // (Sprout-native) are deletion markers; mirror desktop's behavior.
   final deletedIds = <String>{};
   for (final event in events) {
-    if (event.kind != EventKind.deletion) continue;
+    if (event.kind != EventKind.deletion &&
+        event.kind != EventKind.nip29DeleteEvent) {
+      continue;
+    }
     for (final tag in event.tags) {
       if (tag.length >= 2 && tag[0] == 'e') {
         deletedIds.add(tag[1]);

mobile/lib/shared/relay/nostr_models.dart

@@ -11,6 +11,7 @@ abstract final class EventKind {
   static const deletion = 5;
   static const reaction = 7;
   static const streamMessage = 9;
+  static const nip29DeleteEvent = 9005;
   static const presenceUpdate = 20001;
   static const typingIndicator = 20002;
   static const auth = 22242;
@@ -37,6 +38,7 @@ abstract final class EventKind {
   static const channelEventKinds = [
     deletion, // 5
     reaction, // 7
+    nip29DeleteEvent, // 9005 — Sprout-native deletion
     ...channelMessageEventKinds,
     40001, // legacy pre-migration stream messages
     streamMessageEdit, // 40003

mobile/test/features/channels/timeline_message_test.dart

@@ -88,6 +88,23 @@ NostrEvent _deletion({
   sig: '',
 );
 
+NostrEvent _nip29Deletion({
+  required String id,
+  required List<String> targets,
+  int createdAt = 2000,
+}) => NostrEvent(
+  id: id,
+  pubkey: 'alice',
+  createdAt: createdAt,
+  kind: EventKind.nip29DeleteEvent,
+  tags: [
+    ['h', 'ch1'],
+    for (final t in targets) ['e', t],
+  ],
+  content: '',
+  sig: '',
+);
+
 NostrEvent _edit({
   required String id,
   required String targetId,
@@ -311,6 +328,21 @@ void main() {
       expect(result[0].content, 'keep');
     });
 
+    test('filters messages deleted via kind:9005 (Sprout-native)', () {
+      // Agents emit kind:9005 deletes via the CLI. Mobile must mirror desktop
+      // and treat 9005 as a deletion marker, otherwise agent-deleted messages
+      // stay rendered until manual refresh.
+      final events = [
+        _textMsg(id: 'a', content: 'keep'),
+        _textMsg(id: 'b', content: 'delete', createdAt: 1100),
+        _nip29Deletion(id: 'd1', targets: ['b']),
+      ];
+
+      final result = formatTimeline(events);
+      expect(result, hasLength(1));
+      expect(result[0].content, 'keep');
+    });
+
     test('applies edits', () {
       final events = [
         _textMsg(id: 'a', content: 'original'),