fix UserType enum mapping and implement unified API response

- Fix UserType enum mapping issue by adding fromValue method and custom type handler
- Create unified API response structure with ErrorCode constants
- Update AuthController to use standardized response format with proper error codes
- Add verification code authentication system replacing password-based auth
- Improve Swagger documentation with detailed API annotations

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/main/java/com/yundage/chat/controller/UserController.java

@@ -2,6 +2,12 @@ package com.yundage.chat.controller;
 
 import com.yundage.chat.entity.User;
 import com.yundage.chat.mapper.UserMapper;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.*;
 
@@ -10,22 +16,36 @@ import java.util.List;
 
 @RestController
 @RequestMapping("/api/users")
+@Tag(name = "用户管理", description = "用户CRUD操作接口")
+@SecurityRequirement(name = "Bearer Authentication")
 public class UserController {
     
     @Autowired
     private UserMapper userMapper;
     
     @GetMapping
+    @Operation(summary = "获取所有用户", description = "获取系统中所有用户列表")
+    @ApiResponse(responseCode = "200", description = "成功获取用户列表")
     public List<User> getAllUsers() {
         return userMapper.selectAll();
     }
     
     @GetMapping("/{id}")
-    public User getUserById(@PathVariable Long id) {
+    @Operation(summary = "根据ID获取用户", description = "根据用户ID获取用户信息")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "成功获取用户信息"),
+            @ApiResponse(responseCode = "404", description = "用户不存在")
+    })
+    public User getUserById(@Parameter(description = "用户ID") @PathVariable Long id) {
         return userMapper.selectOneById(id);
     }
     
     @PostMapping
+    @Operation(summary = "创建用户", description = "创建新的用户")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "用户创建成功"),
+            @ApiResponse(responseCode = "400", description = "请求参数错误")
+    })
     public User createUser(@RequestBody User user) {
         user.setCreatedAt(LocalDateTime.now());
         user.setUpdatedAt(LocalDateTime.now());
@@ -34,7 +54,13 @@ public class UserController {
     }
     
     @PutMapping("/{id}")
-    public User updateUser(@PathVariable Long id, @RequestBody User user) {
+    @Operation(summary = "更新用户", description = "更新指定用户的信息")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "用户更新成功"),
+            @ApiResponse(responseCode = "404", description = "用户不存在"),
+            @ApiResponse(responseCode = "400", description = "请求参数错误")
+    })
+    public User updateUser(@Parameter(description = "用户ID") @PathVariable Long id, @RequestBody User user) {
         user.setId(id);
         user.setUpdatedAt(LocalDateTime.now());
         userMapper.update(user);
@@ -42,7 +68,12 @@ public class UserController {
     }
     
     @DeleteMapping("/{id}")
-    public void deleteUser(@PathVariable Long id) {
+    @Operation(summary = "删除用户", description = "根据ID删除用户")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "用户删除成功"),
+            @ApiResponse(responseCode = "404", description = "用户不存在")
+    })
+    public void deleteUser(@Parameter(description = "用户ID") @PathVariable Long id) {
         userMapper.deleteById(id);
     }
 }