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/operation_log.py

@@ -0,0 +1,40 @@
+"""
+操作日志数据模型
+"""
+from datetime import datetime
+from sqlalchemy import Column, BigInteger, String, Text, Integer, DateTime, Index
+from sqlalchemy.dialects.postgresql import JSONB
+from app.db.base import Base
+
+
+class OperationLog(Base):
+    """操作日志表"""
+
+    __tablename__ = "operation_logs"
+
+    id = Column(BigInteger, primary_key=True, index=True)
+    operator_id = Column(BigInteger, nullable=False, index=True, comment="操作人ID")
+    operator_name = Column(String(100), nullable=False, comment="操作人姓名")
+    operator_ip = Column(String(50), nullable=True, comment="操作人IP")
+    module = Column(String(50), nullable=False, index=True, comment="模块名称")
+    operation_type = Column(String(50), nullable=False, index=True, comment="操作类型")
+    method = Column(String(10), nullable=False, comment="请求方法(GET/POST/PUT/DELETE等)")
+    url = Column(String(500), nullable=False, comment="请求URL")
+    params = Column(Text, nullable=True, comment="请求参数")
+    result = Column(String(20), default="success", nullable=False, comment="操作结果: success/failed")
+    error_msg = Column(Text, nullable=True, comment="错误信息")
+    duration = Column(Integer, nullable=True, comment="执行时长(毫秒)")
+    user_agent = Column(String(500), nullable=True, comment="用户代理")
+    extra_data = Column(JSONB, nullable=True, comment="额外数据")
+    created_at = Column(DateTime, default=datetime.utcnow, nullable=False, index=True)
+
+    # 索引
+    __table_args__ = (
+        Index("idx_operation_log_operator", "operator_id"),
+        Index("idx_operation_log_module", "module"),
+        Index("idx_operation_log_time", "created_at"),
+        Index("idx_operation_log_result", "result"),
+    )
+
+    def __repr__(self):
+        return f"<OperationLog(id={self.id}, operator={self.operator_name}, module={self.module}, operation={self.operation_type})>"