feat(block2): profiles — your identity card + name/about (NIP-01 kind:0)

Drawer 'Profile' is now live.
- commons_core: ProfileTransport + UserProfile + NostrProfileTransport (kind:0
  publish/fetch), exposed as SocialSession.profile. Round-trip tested against the
  in-process relay (fast dart test).
- app: ProfileStore (local name/about, keystore) + ProfileScreen — shows your
  shareable npub with copy, edits display name + 'about', saves locally and (when
  online) publishes kind:0 so peers can recognise you instead of a raw key.
- Drawer 'Profile' -> /profile (gated like Market/Chat).
- i18n en/es/pt. ProfileStore + profile transport covered by plain/dart tests.

Analyzer clean (both packages).

apps/app_seeds/lib/app.dart

@@ -12,6 +12,7 @@ import 'services/coarse_location.dart';
 import 'services/message_store.dart';
 import 'services/offer_outbox.dart';
 import 'services/onboarding_store.dart';
+import 'services/profile_store.dart';
 import 'services/social_service.dart';
 import 'services/social_settings.dart';
 import 'state/inventory_cubit.dart';
@@ -24,6 +25,7 @@ import 'ui/home_screen.dart';
 import 'ui/intro_screen.dart';
 import 'ui/inventory_list_screen.dart';
 import 'ui/market_screen.dart';
+import 'ui/profile_screen.dart';
 import 'ui/settings_screen.dart';
 import 'ui/theme.dart';
 import 'ui/variety_detail_screen.dart';
@@ -41,6 +43,7 @@ class TaneApp extends StatelessWidget {
     this.location,
     this.outbox,
     this.messageStore,
+    this.profileStore,
     this.showIntro = false,
     this.autoBackup,
     super.key,
@@ -53,6 +56,7 @@ class TaneApp extends StatelessWidget {
           location,
           outbox,
           messageStore,
+          profileStore,
         );
 
   final VarietyRepository repository;
@@ -72,6 +76,9 @@ class TaneApp extends StatelessWidget {
 
   /// Optional persistence for chat history.
   final MessageStore? messageStore;
+
+  /// Optional local store for your own profile (name/about).
+  final ProfileStore? profileStore;
   final bool showIntro;
 
   /// Drives silent periodic backups off the app lifecycle. Null in widget tests
@@ -88,6 +95,7 @@ class TaneApp extends StatelessWidget {
     CoarseLocationProvider? location,
     OfferOutbox? outbox,
     MessageStore? messageStore,
+    ProfileStore? profileStore,
   ) {
     return GoRouter(
       initialLocation: showIntro ? '/intro' : '/',
@@ -112,6 +120,15 @@ class TaneApp extends StatelessWidget {
             path: '/messages',
             builder: (context, state) => ChatListScreen(store: messageStore),
           ),
+        if (social != null && socialSettings != null && profileStore != null)
+          GoRoute(
+            path: '/profile',
+            builder: (context, state) => ProfileScreen(
+              social: social,
+              settings: socialSettings,
+              profileStore: profileStore,
+            ),
+          ),
         if (social != null && socialSettings != null)
           GoRoute(
             path: '/chat/:pubkey',