refactor: 使用数据库管理龙虾配置

- 创建 Lobster 模型 (lobsters/models.py)
  * name, emoji, port, specialty, container
  * app_name, app_id (外部应用信息)
  * created_at, updated_at (自动时间戳)

- 数据库迁移
  * 创建 lobsters 表
  * 导入 7 只龙虾初始数据

- 更新 API 视图
  * lobster_list: 从数据库读取所有龙虾
  * lobster_detail: 从数据库读取单个龙虾
  * 移除硬编码的 LOBSTERS 配置

- 注册 lobsters 应用到 settings.py

优势:
✅ 添加龙虾不需要改代码
✅ 可通过 Django Admin 管理
✅ 支持动态增删改查
✅ 符合 Django 最佳实践

🦄 白泽成为第 7 只数据库龙虾！

code/backend/api/views.py

@@ -7,44 +7,48 @@ from datetime import datetime
 import os
 from pathlib import Path
 import re
-
-# 龙虾配置
-LOBSTERS = [
-    {'id': 1, 'name': '飞行侠', 'emoji': '🦸', 'port': 18789, 'specialty': '主力/通用', 'container': 'openclaw-instance2', 'app_name': 'IT 项目推广运营平台', 'app_id': 'cli_a92413cfb0791bce'},
-    {'id': 2, 'name': '道童', 'emoji': '☯️', 'port': 18889, 'specialty': '道德经注解', 'container': 'openclaw-gateway-2', 'app_name': '道德经新解', 'app_id': 'cli_a9439b614f38dbd2'},
-    {'id': 3, 'name': '墨子', 'emoji': '🔧', 'port': 18689, 'specialty': '代码专家', 'container': 'openclaw-coder', 'app_name': '未配置', 'app_id': ''},
-    {'id': 4, 'name': '织网者', 'emoji': '🕸️', 'port': 18589, 'specialty': '网站制作', 'container': 'openclaw-web', 'app_name': '未配置', 'app_id': ''},
-    {'id': 5, 'name': '费曼', 'emoji': '⚛️', 'port': 18989, 'specialty': '物理研究', 'container': 'openclaw-physics', 'app_name': '未配置', 'app_id': ''},
-    {'id': 6, 'name': '守望者', 'emoji': '👁️', 'port': 18080, 'specialty': '舰队监控', 'container': 'openclaw-watcher', 'app_name': '未配置', 'app_id': ''},
-    {'id': 7, 'name': '白泽', 'emoji': '🦄', 'port': 18389, 'specialty': '秘书/助理', 'container': 'openclaw-secretary', 'app_name': '未配置', 'app_id': ''},
-]
+from lobsters.models import Lobster
 
 @api_view(['GET'])
 def lobster_list(request):
     """获取所有龙虾状态"""
-    lobsters = []
-    for lobster in LOBSTERS:
-        # 检查端口状态（简化版本，实际应该检查端口）
-        status = 'healthy'
-        lobsters.append({
-            **lobster,
-            'status': status,
+    lobsters = Lobster.objects.all()
+    result = []
+    for lobster in lobsters:
+        result.append({
+            'id': lobster.id,
+            'name': lobster.name,
+            'emoji': lobster.emoji,
+            'port': lobster.port,
+            'specialty': lobster.specialty,
+            'container': lobster.container,
+            'app_name': lobster.app_name,
+            'app_id': lobster.app_id,
+            'status': 'healthy',
             'last_check': datetime.now().isoformat()
         })
-    return Response(lobsters)
+    return Response(result)
 
 @api_view(['GET'])
 def lobster_detail(request, lobster_id):
     """获取单个龙虾详情"""
-    for lobster in LOBSTERS:
-        if lobster['id'] == lobster_id:
-            return Response({
-                **lobster,
-                'status': 'healthy',
-                'workspace': f'/home/node/.openclaw/workspace/{lobster["name"].lower()}',
-                'last_check': datetime.now().isoformat()
-            })
-    return Response({'error': '龙虾不存在'}, status=404)
+    try:
+        lobster = Lobster.objects.get(id=lobster_id)
+        return Response({
+            'id': lobster.id,
+            'name': lobster.name,
+            'emoji': lobster.emoji,
+            'port': lobster.port,
+            'specialty': lobster.specialty,
+            'container': lobster.container,
+            'app_name': lobster.app_name,
+            'app_id': lobster.app_id,
+            'status': 'healthy',
+            'workspace': f'/home/node/.openclaw/workspace/{lobster.name.lower()}',
+            'last_check': datetime.now().isoformat()
+        })
+    except Lobster.DoesNotExist:
+        return Response({'error': '龙虾不存在'}, status=404)
 
 @api_view(['GET'])
 def lobster_memory(request, lobster_id):