修复了一些已知问题

backend/schemas/admin.py

@@ -48,7 +48,7 @@ class ImportResult(BaseModel):
 
 class AddAdminRequest(BaseModel):
     """添加管理员请求"""
-    username: str = Field(..., min_length=2, max_length=50, pattern=r'^[a-zA-Z0-9_\u4e00-\u9fa]+$', description="登录账号")
+    username: str = Field(..., min_length=2, max_length=50, pattern=r'^[a-zA-Z0-9_\u4e00-\u9fa5]+$', description="登录账号")
     real_name: str = Field(..., min_length=1, max_length=50, description="真实姓名")
     password: Optional[str] = Field(None, min_length=6, max_length=50, description="密码（不填则自动生成）")
     role_type: str = Field(..., pattern=r'^(班长|学习委员|考勤委员|劳动委员|志愿委员)$', description="角色类型")
@@ -116,4 +116,9 @@ class CreateAssignmentRequest(BaseModel):
     subject_id: int = Field(..., gt=0, description="科目ID")
     title: str = Field(..., min_length=1, max_length=200, description="作业标题")
     description: Optional[str] = Field(None, max_length=1000, description="作业描述")
-    deadline: str = Field(..., min_length=1, max_length=20, description="截止日期")
+    deadline: str = Field(..., min_length=1, max_length=20, description="截止日期")
+
+
+class UnlockUserRequest(BaseModel):
+    """解除用户登录锁定请求"""
+    username: str = Field(..., min_length=1, max_length=50, description="用户名")