feat(permission): 添加权限和审批控制器

- 添加 PermissionController: 权限CRUD、当前用户权限查询
- 添加 ApprovalController: 审批流API接口
- 添加 UserController: 用户角色分配接口
- 修复类型兼容性问题

src/main/java/com/mosquito/project/permission/UserController.java

@@ -0,0 +1,66 @@
+package com.mosquito.project.permission;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+/**
+ * 用户权限控制器 - 处理用户角色分配
+ */
+@RestController
+@RequestMapping("/api/users")
+public class UserController {
+
+    private final UserRoleRepository userRoleRepository;
+    private final RoleRepository roleRepository;
+
+    public UserController(UserRoleRepository userRoleRepository, RoleRepository roleRepository) {
+        this.userRoleRepository = userRoleRepository;
+        this.roleRepository = roleRepository;
+    }
+
+    /**
+     * 获取用户角色
+     */
+    @GetMapping("/{userId}/roles")
+    public ResponseEntity<List<String>> getUserRoles(@PathVariable Long userId) {
+        List<Long> roleIds = userRoleRepository.findRoleIdsByUserId(userId);
+        List<String> roleCodes = roleIds.stream()
+                .map(id -> roleRepository.findById(id))
+                .filter(java.util.Optional::isPresent)
+                .map(java.util.Optional::get)
+                .map(SysRole::getRoleCode)
+                .toList();
+        return ResponseEntity.ok(roleCodes);
+    }
+
+    /**
+     * 分配角色给用户
+     */
+    @PostMapping("/{userId}/roles")
+    public ResponseEntity<Void> assignRoles(@PathVariable Long userId, @RequestBody AssignRolesRequest request) {
+        // 删除现有角色关联
+        userRoleRepository.deleteByUserId(userId);
+
+        // 创建新的角色关联
+        for (Long roleId : request.getRoleIds()) {
+            SysUserRole userRole = new SysUserRole();
+            userRole.setUserId(userId);
+            userRole.setRoleId(roleId);
+            userRoleRepository.save(userRole);
+        }
+
+        return ResponseEntity.ok().build();
+    }
+
+    /**
+     * 角色分配请求
+     */
+    public static class AssignRolesRequest {
+        private List<Long> roleIds;
+
+        public List<Long> getRoleIds() { return roleIds; }
+        public void setRoleIds(List<Long> roleIds) { this.roleIds = roleIds; }
+    }
+}