Jellyfin in the app: account linking and library browser

Integrations links several Jellyfin servers (Quick Connect or
password, app-obtained tokens only, status/reconnect/sign out). The
Host tab's Jellyfin source is a full browser: continue watching, next
up, latest per library, library grids with sort/filter/infinite
scroll, series pages with smart resume/next-up, details, grouped
search, inspector pane on wide screens, keyboard navigation.
MediaPicker selection is now a sealed PickedMedia. Hosting a Jellyfin
pick is interim (host's stream URL) until per-viewer playback lands.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/lib/src/jellyfin/picker_source.dart

@@ -0,0 +1,101 @@
+import 'package:flutter/material.dart';
+
+import '../screens/home/picked_media.dart';
+import '../screens/home/ui.dart';
+import 'accounts.dart';
+import 'browser.dart';
+import 'sign_in_panel.dart';
+
+/// The media picker's Jellyfin source: the library browser once a server
+/// is linked, else an inline add-server panel.
+class JellyfinPickerSource extends StatefulWidget {
+  final JellyfinAccounts accounts;
+  final JellyfinMedia? selected;
+  final ValueChanged<JellyfinMedia> onPick;
+  final VoidCallback? onOpenIntegrations;
+  final VoidCallback? onToggleExpanded;
+  final bool expanded;
+  const JellyfinPickerSource({
+    super.key,
+    required this.accounts,
+    required this.onPick,
+    this.selected,
+    this.onOpenIntegrations,
+    this.onToggleExpanded,
+    this.expanded = false,
+  });
+
+  @override
+  State<JellyfinPickerSource> createState() => _JellyfinPickerSourceState();
+}
+
+class _JellyfinPickerSourceState extends State<JellyfinPickerSource> {
+  @override
+  void initState() {
+    super.initState();
+    widget.accounts.ensureLoaded();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ListenableBuilder(
+      listenable: widget.accounts,
+      builder: (context, _) {
+        final a = widget.accounts;
+        if (!a.loaded) {
+          return const Center(child: CircularProgressIndicator(strokeWidth: 2));
+        }
+        if (a.isEmpty) return _LinkFirst(accounts: a, onOpenIntegrations: widget.onOpenIntegrations);
+        return JellyfinBrowser(
+          key: const ValueKey('media-jellyfin'),
+          accounts: a,
+          selected: widget.selected,
+          onPick: widget.onPick,
+          onOpenIntegrations: widget.onOpenIntegrations,
+          onToggleExpanded: widget.onToggleExpanded,
+          expanded: widget.expanded,
+        );
+      },
+    );
+  }
+}
+
+class _LinkFirst extends StatelessWidget {
+  final JellyfinAccounts accounts;
+  final VoidCallback? onOpenIntegrations;
+  const _LinkFirst({required this.accounts, this.onOpenIntegrations});
+
+  @override
+  Widget build(BuildContext context) {
+    return SingleChildScrollView(
+      key: const ValueKey('media-jellyfin'),
+      child: Align(
+        alignment: Alignment.topLeft,
+        child: ConstrainedBox(
+          constraints: const BoxConstraints(maxWidth: 560),
+          child: Panel(
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                const Text('Link a Jellyfin server to browse it here. '
+                    'You can manage linked servers in Integrations.',
+                    style: TextStyle(color: Colors.grey)),
+                const SizedBox(height: kGap),
+                JellyfinSignInPanel(accounts: accounts),
+                if (onOpenIntegrations != null) ...[
+                  const SizedBox(height: 8),
+                  Align(
+                    alignment: Alignment.centerLeft,
+                    child: TextButton(
+                        onPressed: onOpenIntegrations, child: const Text('Open Integrations')),
+                  ),
+                ],
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}