Initial commit: Fabled Android app

Flutter Android client for FabledAssistant with:
- Session-cookie auth via persistent cookie jar (Dio + cookie_jar)
- OAuth/SSO login via in-app WebView (flutter_inappwebview)
- Notes: list, detail (markdown render), create/edit
- Tasks: list with status tabs, create/edit with priority
- Chat: SSE streaming bubbles, conversation management
- Quick Capture FAB for rapid note/task creation
- Settings screen (change server URL, logout)
- Android home screen widget → opens chat
- Riverpod state management, go_router navigation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/data/models/conversation.dart

@@ -0,0 +1,20 @@
+class Conversation {
+  final int id;
+  final String title;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+
+  const Conversation({
+    required this.id,
+    required this.title,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  factory Conversation.fromJson(Map<String, dynamic> json) => Conversation(
+        id: json['id'] as int,
+        title: json['title'] as String,
+        createdAt: DateTime.parse(json['created_at'] as String),
+        updatedAt: DateTime.parse(json['updated_at'] as String),
+      );
+}