v2.1: 新增通知提醒功能和安全增强

功能:
- 通知提醒系统: 还款日提醒、逾期提醒、系统消息横幅、登录时通知
- 通知中心UI: 铃铛图标 + 下拉列表 + 未读徽章
- 定时任务: APScheduler 每小时检查即将到期的还款
- 邮件通知: SMTP 发送还款提醒和安全警告
- 异常登录通知: 3/5/10次失败触发网页和邮件通知

安全:
- 登录安全告警: 异常登录次数达到阈值时发送通知
- 密码重置链接: 一次性使用, 5分钟有效期
- 登录频率限制: IP级和账户级限制

技术:
- 后端: FastAPI + SQLAlchemy + PostgreSQL
- 前端: 纯 HTML/CSS/JS
- 部署: Docker Compose (新增 build 配置)

backend/app/schemas/schemas.py

@@ -0,0 +1,256 @@
+from pydantic import BaseModel
+from datetime import datetime
+
+
+class RegisterRequest(BaseModel):
+    account: str
+    password: str
+    nickname: str = ""
+    group_id: int | None = None
+
+
+class LoginRequest(BaseModel):
+    account: str
+    password: str
+
+
+class TokenResponse(BaseModel):
+    access_token: str
+    refresh_token: str
+    token_type: str = "bearer"
+
+
+class RefreshRequest(BaseModel):
+    refresh_token: str
+
+
+class UserProfile(BaseModel):
+    id: int
+    account: str
+    nickname: str
+    real_email: str = ""
+    role: str
+    status: str
+    group_id: int | None = None
+    group_name: str = ""
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class ChangePasswordRequest(BaseModel):
+    old_password: str
+    new_password: str
+
+
+class GroupCreate(BaseModel):
+    name: str
+    description: str = ""
+
+
+class GroupResponse(BaseModel):
+    id: int
+    name: str
+    description: str
+    member_count: int = 0
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class GroupMemberAdd(BaseModel):
+    user_id: int
+
+
+class LoanCreate(BaseModel):
+    name: str
+    date: str
+    amount: float
+    rate: float
+    periods: int
+    method: str
+    purpose: str = ""
+    schedule: list[dict] = []
+    paid: list[int] = []
+
+
+class LoanResponse(BaseModel):
+    id: int
+    name: str
+    date: str
+    amount: float
+    rate: float
+    periods: int
+    method: str
+    purpose: str
+    schedule: list[dict]
+    paid: list[int]
+    user_id: int
+    owner_name: str = ""
+
+
+class DebtCreate(BaseModel):
+    creditor_name: str
+    amount: int
+    borrow_date: datetime
+    interest_rate: float
+    rate_type: str = "annual"
+    repayment_method: str
+    period_count: int
+    period_unit: str = "month"
+    notes: str = ""
+
+
+class DebtUpdate(BaseModel):
+    creditor_name: str | None = None
+    amount: int | None = None
+    borrow_date: datetime | None = None
+    interest_rate: float | None = None
+    rate_type: str | None = None
+    repayment_method: str | None = None
+    period_count: int | None = None
+    period_unit: str | None = None
+    notes: str | None = None
+
+
+class DebtResponse(BaseModel):
+    id: int
+    user_id: int
+    creditor_name: str
+    amount: int
+    borrow_date: datetime
+    interest_rate: float
+    rate_type: str
+    repayment_method: str
+    period_count: int
+    period_unit: str
+    status: str
+    notes: str
+    created_at: datetime
+    total_paid: int = 0
+    total_interest: int = 0
+    owner_name: str = ""
+
+    class Config:
+        from_attributes = True
+
+
+class RepaymentPlanResponse(BaseModel):
+    id: int
+    debt_id: int
+    due_date: datetime
+    principal_due: int
+    interest_due: int
+    total_due: int
+    status: str
+
+    class Config:
+        from_attributes = True
+
+
+class RepaymentRecordCreate(BaseModel):
+    debt_id: int
+    plan_id: int | None = None
+    amount: int
+    paid_date: datetime
+    notes: str = ""
+
+
+class RepaymentRecordResponse(BaseModel):
+    id: int
+    debt_id: int
+    plan_id: int | None
+    amount: int
+    paid_date: datetime
+    notes: str
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class DashboardSummary(BaseModel):
+    total_debt: int
+    total_paid: int
+    total_remaining: int
+    active_count: int
+    overdue_count: int
+    paid_count: int
+    upcoming_payments: list[dict]
+
+
+class AdminUserResponse(BaseModel):
+    id: int
+    account: str
+    nickname: str
+    real_email: str = ""
+    role: str
+    status: str
+    group_id: int | None = None
+    group_name: str = ""
+    created_at: datetime
+    debt_count: int = 0
+    total_amount: int = 0
+
+    class Config:
+        from_attributes = True
+
+
+class AdminDashboard(BaseModel):
+    total_users: int
+    active_debts: int
+    total_amount: int
+    overdue_count: int
+    rate_distribution: dict
+    status_distribution: dict
+
+
+class SystemSettingUpdate(BaseModel):
+    value: str
+
+
+class NotificationResponse(BaseModel):
+    id: int
+    user_id: int
+    title: str
+    message: str
+    type: str
+    is_read: int
+    related_debt_id: int | None = None
+    related_plan_id: int | None = None
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class NotificationListResponse(BaseModel):
+    items: list[NotificationResponse]
+    total: int
+    unread: int
+
+
+class EmailServiceConfig(BaseModel):
+    smtp_host: str = ""
+    smtp_port: int = 465
+    smtp_user: str = ""
+    smtp_password: str = ""
+    smtp_from: str = ""
+    smtp_use_tls: bool = True
+
+
+class ForgotPasswordRequest(BaseModel):
+    account: str
+
+
+class VerifyResetCodeRequest(BaseModel):
+    account: str
+    code: str
+
+
+class ResetPasswordRequest(BaseModel):
+    account: str
+    code: str
+    new_password: str