fix: 修复多个关键问题

- 修复前端路由守卫：未登录时不显示提示，直接跳转登录页
- 修复API拦截器：401错误不显示提示，直接跳转
- 增强验证码显示：图片尺寸从120x40增加到200x80
- 增大验证码字体：从28号增加到48号
- 优化验证码字符：排除易混淆的0和1
- 减少干扰线：从5条减少到3条，添加背景色优化
- 增强登录API日志：添加详细的调试日志
- 增强验证码生成和验证日志
- 优化异常处理和错误追踪

影响文件：
- src/router/index.ts
- src/api/request.ts
- app/services/auth_service.py
- app/api/v1/auth.py
- app/schemas/user.py

测试状态：
- 前端构建通过
- 后端语法检查通过
- 验证码显示效果优化完成

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

app/models/__init__.py

@@ -0,0 +1,43 @@
+"""
+数据模型模块初始化
+"""
+from app.models.user import User, Role, UserRole, Permission, RolePermission
+from app.models.device_type import DeviceType, DeviceTypeField
+from app.models.organization import Organization
+from app.models.brand_supplier import Brand, Supplier
+from app.models.asset import Asset, AssetStatusHistory
+from app.models.allocation import AssetAllocationOrder, AssetAllocationItem
+from app.models.maintenance import MaintenanceRecord
+from app.models.transfer import AssetTransferOrder, AssetTransferItem
+from app.models.recovery import AssetRecoveryOrder, AssetRecoveryItem
+from app.models.system_config import SystemConfig
+from app.models.operation_log import OperationLog
+from app.models.notification import Notification, NotificationTemplate
+from app.models.file_management import UploadedFile
+
+__all__ = [
+    "User",
+    "Role",
+    "UserRole",
+    "Permission",
+    "RolePermission",
+    "DeviceType",
+    "DeviceTypeField",
+    "Organization",
+    "Brand",
+    "Supplier",
+    "Asset",
+    "AssetStatusHistory",
+    "AssetAllocationOrder",
+    "AssetAllocationItem",
+    "MaintenanceRecord",
+    "AssetTransferOrder",
+    "AssetTransferItem",
+    "AssetRecoveryOrder",
+    "AssetRecoveryItem",
+    "SystemConfig",
+    "OperationLog",
+    "Notification",
+    "NotificationTemplate",
+    "UploadedFile",
+]