feat(profiles): show the first linked connection's user picture

A local profile had no picture of its own and always fell back to
initials. It now borrows the user picture of the connection it was
linked to first — oldest Connection.createdAt, ties broken by
connection id, since the join table carries no creation time.

Jellyfin links resolve to /Users/{id}/Images/Primary, keyed by the
PrimaryImageTag now captured at authentication and refreshed from the
/Users/Me body checkHealth already fetches. That endpoint is anonymous
on every Jellyfin release, so the URL carries no api_key and the access
token stays out of the image cache key. Plex links resolve the Home
user the link points at against PlexHomeService's live cache, so no
account-level lookup is needed and the picture tracks Plex's own
refresh.

The picture is derived per snapshot and never written back onto a
Profile: ProfileDetailScreen upserts the model it holds, so a
persisted URL would go stale and outlive the connection it came from.
Plex Home profiles are untouched, including one whose Plex avatar is
unset — it keeps its initials rather than borrowing a lent connection's
picture.

close #1667

test/screens/discover_screen_test.dart

@@ -104,6 +104,7 @@ void main() {
       registry: profileRegistry,
       plexHome: plexHome,
       connections: connectionRegistry,
+      profileConnections: profileConnectionRegistry,
       storage: storage,
     );
     final discoverProvider = DiscoverProvider(
@@ -295,6 +296,7 @@ void main() {
       registry: profileRegistry,
       plexHome: plexHome,
       connections: connectionRegistry,
+      profileConnections: profileConnectionRegistry,
       storage: storage,
     );
     final discoverProvider = DiscoverProvider(
@@ -406,6 +408,7 @@ void main() {
       registry: profileRegistry,
       plexHome: plexHome,
       connections: connectionRegistry,
+      profileConnections: profileConnectionRegistry,
       storage: storage,
     );
     final discoverProvider = DiscoverProvider(

test/screens/profile/profile_detail_screen_test.dart

@@ -7,6 +7,7 @@ import 'package:plezy/connection/connection_registry.dart';
 import 'package:plezy/database/app_database.dart';
 import 'package:plezy/focus/input_mode_tracker.dart';
 import 'package:plezy/i18n/strings.g.dart';
+import 'package:plezy/profiles/active_profile_provider.dart';
 import 'package:plezy/profiles/plex_home_service.dart';
 import 'package:plezy/profiles/profile.dart';
 import 'package:plezy/profiles/profile_connection.dart';
@@ -49,7 +50,19 @@ void main() {
       storage: storage,
       plexHomeUserFetcher: (_) async => const [],
     );
+    // The screen reads its avatar through this provider, exactly as it does
+    // under the app-lifetime scope in main.dart. Left uninitialized: this test
+    // is about TV back handling, and an idle provider yields no avatar without
+    // opening stream subscriptions the test would have to settle.
+    final activeProfile = ActiveProfileProvider(
+      registry: profiles,
+      plexHome: plexHome,
+      connections: connections,
+      profileConnections: profileConnections,
+      storage: storage,
+    );
     addTearDown(() async {
+      activeProfile.dispose();
       await plexHome.dispose();
       await db.close();
     });
@@ -62,6 +75,7 @@ void main() {
             Provider<ProfileConnectionRegistry>.value(value: profileConnections),
             Provider<ConnectionRegistry>.value(value: connections),
             Provider<PlexHomeService>.value(value: plexHome),
+            ChangeNotifierProvider<ActiveProfileProvider>.value(value: activeProfile),
           ],
           child: InputModeTracker(
             child: MaterialApp(

test/screens/profile/profile_switch_screen_test.dart

@@ -9,6 +9,7 @@ import 'package:plezy/i18n/strings.g.dart';
 import 'package:plezy/profiles/active_profile_provider.dart';
 import 'package:plezy/profiles/plex_home_service.dart';
 import 'package:plezy/profiles/profile.dart';
+import 'package:plezy/profiles/profile_avatar.dart';
 import 'package:plezy/profiles/profile_connection.dart';
 import 'package:plezy/profiles/profile_connection_registry.dart';
 import 'package:plezy/profiles/profile_registry.dart';
@@ -44,6 +45,7 @@ void main() {
       registry: profiles,
       plexHome: plexHome,
       connections: connections,
+      profileConnections: profileConnections,
       storage: storage,
     );
     addTearDown(() async {
@@ -106,6 +108,7 @@ void main() {
       registry: profiles,
       plexHome: plexHome,
       connections: connections,
+      profileConnections: profileConnections,
       storage: storage,
     );
     addTearDown(() async {
@@ -132,6 +135,87 @@ void main() {
 
     expect(tester.getTopLeft(find.text('Kids')).dy, lessThan(tester.getTopLeft(find.text('Owner')).dy));
   });
+
+  testWidgets('passes derived Jellyfin avatar URLs only to linked profile tiles', (tester) async {
+    final db = AppDatabase.forTesting(NativeDatabase.memory());
+    final linkedProfile = Profile.local(id: 'local-linked', displayName: 'Linked', createdAt: DateTime(2026, 1, 1));
+    final unlinkedProfile = Profile.local(
+      id: 'local-unlinked',
+      displayName: 'Unlinked',
+      createdAt: DateTime(2026, 1, 2),
+    );
+    final jellyfin = JellyfinConnection(
+      id: 'jf-machine/jf-user',
+      baseUrl: 'https://jellyfin.example',
+      serverName: 'Jellyfin',
+      serverMachineId: 'jf-machine',
+      userId: 'jf-user',
+      userName: 'Linked',
+      accessToken: 'secret-token',
+      deviceId: 'device-1',
+      primaryImageTag: 'primary-tag',
+      createdAt: DateTime(2025, 12, 1),
+    );
+    final link = ProfileConnection(
+      profileId: linkedProfile.id,
+      connectionId: jellyfin.id,
+      userIdentifier: jellyfin.userId,
+    );
+    final profiles = _FakeProfileRegistry(db, [linkedProfile, unlinkedProfile]);
+    final connections = _FakeConnectionRegistry(db, [jellyfin]);
+    final profileConnections = _FakeProfileConnectionRegistry(db, [link]);
+    final storage = await StorageService.getInstance();
+    final plexHome = PlexHomeService(
+      connections: connections,
+      profileConnections: profileConnections,
+      storage: storage,
+      plexHomeUserFetcher: (_) async => const [],
+    );
+    final activeProfile = ActiveProfileProvider(
+      registry: profiles,
+      plexHome: plexHome,
+      connections: connections,
+      profileConnections: profileConnections,
+      storage: storage,
+    );
+    addTearDown(() async {
+      activeProfile.dispose();
+      await plexHome.dispose();
+      await db.close();
+    });
+
+    await tester.pumpWidget(
+      TranslationProvider(
+        child: MultiProvider(
+          providers: [
+            Provider<ProfileRegistry>.value(value: profiles),
+            Provider<ProfileConnectionRegistry>.value(value: profileConnections),
+            Provider<ConnectionRegistry>.value(value: connections),
+            Provider<PlexHomeService>.value(value: plexHome),
+            ChangeNotifierProvider<ActiveProfileProvider>.value(value: activeProfile),
+          ],
+          child: MaterialApp(theme: monoTheme(dark: true), home: const ProfileSwitchScreen()),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    final linkedAvatar = tester.widget<ProfileAvatar>(
+      find.byWidgetPredicate((widget) => widget is ProfileAvatar && widget.profile?.id == linkedProfile.id),
+    );
+    final unlinkedAvatar = tester.widget<ProfileAvatar>(
+      find.byWidgetPredicate((widget) => widget is ProfileAvatar && widget.profile?.id == unlinkedProfile.id),
+    );
+    expect(linkedAvatar.avatarUrl, isNotNull);
+    expect(
+      linkedAvatar.avatarUrl,
+      'https://jellyfin.example/Users/jf-user/Images/Primary?tag=primary-tag&maxWidth=240&maxHeight=240',
+    );
+    expect(unlinkedAvatar.avatarUrl, isNull);
+
+    await tester.pumpWidget(const SizedBox.shrink());
+    await tester.pump();
+  });
 }
 
 class _FakeProfileRegistry extends ProfileRegistry {
@@ -147,18 +231,22 @@ class _FakeProfileRegistry extends ProfileRegistry {
 }
 
 class _FakeConnectionRegistry extends ConnectionRegistry {
-  _FakeConnectionRegistry(super.db);
+  final List<Connection> _connections;
+
+  _FakeConnectionRegistry(super.db, [this._connections = const []]);
 
   @override
-  Stream<List<Connection>> watchConnections() => Stream.value(const []);
+  Stream<List<Connection>> watchConnections() => Stream.value(_connections);
 
   @override
-  Future<List<Connection>> list() async => const [];
+  Future<List<Connection>> list() async => _connections;
 }
 
 class _FakeProfileConnectionRegistry extends ProfileConnectionRegistry {
-  _FakeProfileConnectionRegistry(super.db);
+  final List<ProfileConnection> _profileConnections;
+
+  _FakeProfileConnectionRegistry(super.db, [this._profileConnections = const []]);
 
   @override
-  Stream<List<ProfileConnection>> watchAll() => Stream.value(const []);
+  Stream<List<ProfileConnection>> watchAll() => Stream.value(_profileConnections);
 }

test/screens/profile/profile_teardown_test.dart

@@ -268,6 +268,7 @@ Future<_Harness> _pumpHarness(
     registry: profileRegistry,
     plexHome: plexHome,
     connections: connections,
+    profileConnections: profileConnections,
     storage: storage,
   );
   final profile = Profile.local(id: 'active', displayName: 'Active', createdAt: DateTime(2026, 1, 1));

test/screens/settings/add_jellyfin_screen_test.dart

@@ -168,6 +168,7 @@ class _NoWatchActiveProfileProvider extends ActiveProfileProvider {
     required super.registry,
     required super.plexHome,
     required super.connections,
+    required super.profileConnections,
     required super.storage,
   });
 
@@ -242,6 +243,7 @@ class _RouteHarness {
       registry: profiles,
       plexHome: plexHome,
       connections: connections,
+      profileConnections: profileConnections,
       storage: storage,
     );
     final manager = _CountingJellyfinManager();

test/screens/settings/connection_persistence_test.dart

@@ -79,6 +79,7 @@ class _RejectingActiveProfileProvider extends ActiveProfileProvider {
     required super.registry,
     required super.plexHome,
     required super.connections,
+    required super.profileConnections,
     required super.storage,
   });
 
@@ -91,6 +92,7 @@ class _ThrowingActiveProfileProvider extends ActiveProfileProvider {
     required super.registry,
     required super.plexHome,
     required super.connections,
+    required super.profileConnections,
     required super.storage,
   });
 
@@ -184,7 +186,13 @@ void main() {
     );
     activeProfiles =
         activeFactory?.call(profiles, plexHome, connections, storage) ??
-        ActiveProfileProvider(registry: profiles, plexHome: plexHome, connections: connections, storage: storage);
+        ActiveProfileProvider(
+          registry: profiles,
+          plexHome: plexHome,
+          connections: connections,
+          profileConnections: profileConnections,
+          storage: storage,
+        );
     if (initializeActive) await tester.runAsync(activeProfiles.initialize);
     await tester.pumpWidget(
       MultiProvider(
@@ -347,6 +355,7 @@ void main() {
         registry: profiles,
         plexHome: plexHome,
         connections: connections,
+        profileConnections: profileConnections,
         storage: storage,
       ),
     );
@@ -388,6 +397,7 @@ void main() {
         registry: profiles,
         plexHome: plexHome,
         connections: connections,
+        profileConnections: profileConnections,
         storage: storage,
       ),
     );

test/screens/settings/settings_screen_test.dart

@@ -642,7 +642,12 @@ Future<_SettingsHarness> _pumpSettingsScreen(
     profileConnections: profileConnections,
     plexHomeUserFetcher: (_) async => const [],
   );
-  final activeProfile = ActiveProfileProvider(registry: profiles, plexHome: plexHome, connections: connections);
+  final activeProfile = ActiveProfileProvider(
+    registry: profiles,
+    plexHome: plexHome,
+    connections: connections,
+    profileConnections: profileConnections,
+  );
   final libraries = LibrariesProvider();
   final hiddenLibraries = HiddenLibrariesProvider(storageService: _FakeHiddenLibrariesStorage());
   await hiddenLibraries.ensureInitialized();