feat: 添加 API Key 发布功能

- 新增 ApiKey 模型，支持 API 密钥认证
- 添加 require_api_key 装饰器实现 API 认证
- 实现 5 个站点管理 API 接口 (GET/POST/PUT/DELETE)
- 添加后台 API Key 管理界面
- 添加数据库迁移脚本

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

models.py

@@ -155,6 +155,46 @@ class Admin(UserMixin, db.Model):
     def __repr__(self):
         return f'<Admin {self.username}>'
 
+
+class ApiKey(db.Model):
+    """API密钥模型"""
+    __tablename__ = 'api_keys'
+
+    id = db.Column(db.Integer, primary_key=True)
+    key = db.Column(db.String(64), unique=True, nullable=False, comment='API密钥')
+    name = db.Column(db.String(50), nullable=False, comment='密钥名称')
+    permissions = db.Column(db.String(200), default='site:read,site:write', comment='权限列表')
+    is_active = db.Column(db.Boolean, default=True, comment='是否启用')
+    created_at = db.Column(db.DateTime, default=datetime.now, comment='创建时间')
+    last_used = db.Column(db.DateTime, comment='最后使用时间')
+    usage_count = db.Column(db.Integer, default=0, comment='使用次数')
+
+    def __repr__(self):
+        return f'<ApiKey {self.name}>'
+
+    def has_permission(self, permission):
+        """检查是否拥有指定权限"""
+        if not self.is_active:
+            return False
+        perms = self.permissions.split(',') if self.permissions else []
+        return permission.strip() in [p.strip() for p in perms]
+
+    def to_dict(self, include_key=False):
+        """转换为字典"""
+        result = {
+            'id': self.id,
+            'name': self.name,
+            'permissions': self.permissions,
+            'is_active': self.is_active,
+            'created_at': self.created_at.strftime('%Y-%m-%d %H:%M:%S') if self.created_at else None,
+            'last_used': self.last_used.strftime('%Y-%m-%d %H:%M:%S') if self.last_used else None,
+            'usage_count': self.usage_count
+        }
+        if include_key:
+            result['key'] = self.key
+        return result
+
+
 class PromptTemplate(db.Model):
     """AI提示词模板模型"""
     __tablename__ = 'prompt_templates'