feat(block2): show contact names (resolve peers' published profiles)

Closes the profile loop — peers now appear by name, not a raw key.
- ProfileCache: keystore-backed cache of peers' published display names (works
  offline) + shortPubkey() fallback.
- Chat: the app bar shows the peer's name (cached first, then freshened from
  their kind:0 over the session); falls back to a short key.
- Inbox: each conversation shows the cached name, and missing names are resolved
  over one session and cached.
- Wired via DI + TaneApp(profileCache).

Analyzer clean; ProfileCache covered by a plain test.

apps/app_seeds/lib/ui/chat_list_screen.dart

@@ -1,16 +1,30 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 
 import '../i18n/strings.g.dart';
 import '../services/message_store.dart';
+import '../services/profile_cache.dart';
+import '../services/social_service.dart';
+import '../services/social_settings.dart';
 import 'theme.dart';
 
-/// The messages inbox: past conversations, newest first. Tapping one opens the
-/// chat. Reached from the drawer's "Chat" entry.
+/// The messages inbox: past conversations, newest first. Shows each peer's
+/// published name (falling back to a short key), and opens the chat on tap.
 class ChatListScreen extends StatefulWidget {
-  const ChatListScreen({required this.store, super.key});
+  const ChatListScreen({
+    required this.store,
+    this.social,
+    this.settings,
+    this.profileCache,
+    super.key,
+  });
 
   final MessageStore store;
+  final SocialService? social;
+  final SocialSettings? settings;
+  final ProfileCache? profileCache;
 
   @override
   State<ChatListScreen> createState() => _ChatListScreenState();
@@ -18,6 +32,7 @@ class ChatListScreen extends StatefulWidget {
 
 class _ChatListScreenState extends State<ChatListScreen> {
   List<ChatSummary>? _items;
+  final Map<String, String> _names = {};
 
   @override
   void initState() {
@@ -27,7 +42,43 @@ class _ChatListScreenState extends State<ChatListScreen> {
 
   Future<void> _load() async {
     final items = await widget.store.conversations();
-    if (mounted) setState(() => _items = items);
+    final cache = widget.profileCache;
+    if (cache != null) {
+      for (final c in items) {
+        final name = await cache.name(c.peerPubkey);
+        if (name != null) _names[c.peerPubkey] = name;
+      }
+    }
+    if (!mounted) return;
+    setState(() => _items = items);
+    unawaited(_resolveMissingNames(items));
+  }
+
+  /// Fetches published names for peers we don't have cached yet, over one
+  /// session. Best effort; the list already shows short keys meanwhile.
+  Future<void> _resolveMissingNames(List<ChatSummary> items) async {
+    final social = widget.social;
+    final settings = widget.settings;
+    final cache = widget.profileCache;
+    if (social == null || settings == null || cache == null) return;
+    final missing =
+        items.map((c) => c.peerPubkey).where((p) => !_names.containsKey(p));
+    if (missing.isEmpty) return;
+    final relays = await settings.relayUrls();
+    if (relays.isEmpty) return;
+    try {
+      final session = await social.openSession(relays);
+      for (final peer in missing) {
+        final profile = await session.profile.fetch(peer);
+        if (profile != null && profile.name.isNotEmpty) {
+          await cache.setName(peer, profile.name);
+          if (mounted) setState(() => _names[peer] = profile.name);
+        }
+      }
+      await session.close();
+    } catch (_) {
+      // offline / unreachable — short keys stay.
+    }
   }
 
   @override
@@ -59,7 +110,8 @@ class _ChatListScreenState extends State<ChatListScreen> {
                         backgroundColor: seedAvatar,
                         child: Icon(Icons.person, color: seedOnAvatar),
                       ),
-                      title: Text(_shortId(c.peerPubkey)),
+                      title: Text(_names[c.peerPubkey] ??
+                          shortPubkey(c.peerPubkey)),
                       subtitle: Text(
                         c.lastText,
                         maxLines: 1,
@@ -72,8 +124,3 @@ class _ChatListScreenState extends State<ChatListScreen> {
     );
   }
 }
-
-/// A compact, human-ish rendering of a public key until we resolve names.
-String _shortId(String pubkey) => pubkey.length <= 12
-    ? pubkey
-    : '${pubkey.substring(0, 6)}…${pubkey.substring(pubkey.length - 4)}';

apps/app_seeds/lib/ui/chat_screen.dart

@@ -5,6 +5,7 @@ import 'package:flutter_bloc/flutter_bloc.dart';
 
 import '../i18n/strings.g.dart';
 import '../services/message_store.dart';
+import '../services/profile_cache.dart';
 import '../services/social_service.dart';
 import '../services/social_settings.dart';
 import '../state/messages_cubit.dart';
@@ -20,6 +21,7 @@ class ChatScreen extends StatefulWidget {
     required this.settings,
     required this.peerPubkey,
     this.messageStore,
+    this.profileCache,
     super.key,
   });
 
@@ -30,6 +32,9 @@ class ChatScreen extends StatefulWidget {
   /// Optional persistence for chat history (keystore-backed); null in tests.
   final MessageStore? messageStore;
 
+  /// Optional cache of peer display names; null in tests.
+  final ProfileCache? profileCache;
+
   @override
   State<ChatScreen> createState() => _ChatScreenState();
 }
@@ -39,6 +44,7 @@ class _ChatScreenState extends State<ChatScreen> {
   MessagesCubit? _messages;
   TrustCubit? _trust;
   bool _loading = true;
+  String? _peerName;
   final _input = TextEditingController();
 
   @override
@@ -59,6 +65,7 @@ class _ChatScreenState extends State<ChatScreen> {
         session = null;
       }
     }
+    final cachedName = await widget.profileCache?.name(widget.peerPubkey);
     if (!mounted) {
       await session?.close();
       return;
@@ -77,8 +84,25 @@ class _ChatScreenState extends State<ChatScreen> {
       _session = session;
       _messages = messages;
       _trust = trust;
+      _peerName = cachedName;
       _loading = false;
     });
+
+    // Freshen the peer's name from their published profile.
+    final live = session;
+    if (live != null && widget.profileCache != null) {
+      unawaited(() async {
+        try {
+          final profile = await live.profile.fetch(widget.peerPubkey);
+          if (profile != null && profile.name.isNotEmpty && mounted) {
+            await widget.profileCache!.setName(widget.peerPubkey, profile.name);
+            setState(() => _peerName = profile.name);
+          }
+        } catch (_) {
+          // best effort
+        }
+      }());
+    }
   }
 
   Future<void> _send() async {
@@ -100,11 +124,12 @@ class _ChatScreenState extends State<ChatScreen> {
 
   @override
   Widget build(BuildContext context) {
-    final t = context.t;
     final messages = _messages;
     final trust = _trust;
     return Scaffold(
-      appBar: AppBar(title: Text(t.chat.title)),
+      appBar: AppBar(
+        title: Text(_peerName ?? shortPubkey(widget.peerPubkey)),
+      ),
       body: _loading || messages == null || trust == null
           ? const Center(child: CircularProgressIndicator())
           : MultiBlocProvider(