feat: prompts from workspace

lib/core/models/prompt.dart

@@ -0,0 +1,69 @@
+import 'package:flutter/foundation.dart';
+
+@immutable
+class Prompt {
+  const Prompt({
+    required this.command,
+    required this.title,
+    required this.content,
+    this.accessControl,
+    this.userId,
+    this.timestamp,
+  });
+
+  final String command;
+  final String title;
+  final String content;
+  final Map<String, dynamic>? accessControl;
+  final String? userId;
+  final int? timestamp;
+
+  factory Prompt.fromJson(Map<String, dynamic> json) {
+    final rawCommand = (json['command'] as String? ?? '').trim();
+    final normalizedCommand = rawCommand.startsWith('/')
+        ? rawCommand
+        : (rawCommand.isEmpty ? rawCommand : '/$rawCommand');
+
+    return Prompt(
+      command: normalizedCommand,
+      title: json['title'] as String? ?? '',
+      content: json['content'] as String? ?? '',
+      accessControl: json['access_control'] is Map<String, dynamic>
+          ? Map<String, dynamic>.from(json['access_control'] as Map)
+          : null,
+      userId: json['user_id'] as String?,
+      timestamp: json['timestamp'] is int
+          ? json['timestamp'] as int
+          : int.tryParse('${json['timestamp']}'),
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return <String, dynamic>{
+      'command': command,
+      'title': title,
+      'content': content,
+      if (accessControl != null) 'access_control': accessControl,
+      if (userId != null) 'user_id': userId,
+      if (timestamp != null) 'timestamp': timestamp,
+    };
+  }
+
+  Prompt copyWith({
+    String? command,
+    String? title,
+    String? content,
+    Map<String, dynamic>? accessControl,
+    String? userId,
+    int? timestamp,
+  }) {
+    return Prompt(
+      command: command ?? this.command,
+      title: title ?? this.title,
+      content: content ?? this.content,
+      accessControl: accessControl ?? this.accessControl,
+      userId: userId ?? this.userId,
+      timestamp: timestamp ?? this.timestamp,
+    );
+  }
+}