feat(borrow): add borrow service interfaces and search capability

- Add BorrowService and AdminBorrowService interfaces
- Add BorrowInfoDto for borrow record data transfer
- Rename UserLoginDTO to UserLoginDto for naming consistency
- Update dashboard to use structured borrow record mapping

src/main/kotlin/com/msksbr/bookmgr/controller/AdminBorrowController.kt

@@ -7,8 +7,7 @@ import org.springframework.web.bind.annotation.RestController
 * 路径前缀（待定）：/api/admin/borrows
 *
 * 计划接口：
-*   - 全量借阅记录查询
-*   - 手动归还
+*   - 全量搜索借阅记录
 */
 @RestController
 class AdminBorrowController {

src/main/kotlin/com/msksbr/bookmgr/controller/AuthController.kt

@@ -2,7 +2,7 @@ package com.msksbr.bookmgr.controller
 
 import com.msksbr.bookmgr.config.IpExtractor
 import com.msksbr.bookmgr.config.JwtUtils
-import com.msksbr.bookmgr.dto.UserLoginDTO
+import com.msksbr.bookmgr.dto.UserLoginDto
 import com.msksbr.bookmgr.script.log
 import com.msksbr.bookmgr.service.AuthService
 import com.msksbr.bookmgr.template.Result
@@ -44,7 +44,7 @@ class AuthController(
     fun login(
         @Valid
         @RequestBody
-        loginDTO: UserLoginDTO,
+        loginDTO: UserLoginDto,
         request: HttpServletRequest
     ): Result<out Any?> {
         log.info("[Auth] login attempt: user={}, ip={}", loginDTO.username, ipExtractor.getRealIp(request))

src/main/kotlin/com/msksbr/bookmgr/dto/BorrowInfoDto.kt

@@ -0,0 +1,14 @@
+package com.msksbr.bookmgr.dto
+
+import com.msksbr.bookmgr.entity.Book
+import java.util.Date
+
+class BorrowInfoDto(
+    val id: Long,
+    val book: Book,
+    val userId: Long,
+    val username: String,
+    val borrowTime: Date,
+    val returnTime: Date?,
+    val string: String
+)

src/main/kotlin/com/msksbr/bookmgr/dto/UserLoginDto.kt

@@ -11,7 +11,7 @@ import jakarta.validation.constraints.NotBlank
 *
 * 字段类型为可空 String?，但运行时被 @Valid + @NotBlank 保证非空
 */
-data class UserLoginDTO(
+data class UserLoginDto(
     @NotBlank(message = "username is required")
     val username: String?,
     @NotBlank(message = "password is required")

src/main/kotlin/com/msksbr/bookmgr/service/AdminBorrowService.kt

@@ -0,0 +1,5 @@
+package com.msksbr.bookmgr.service
+
+interface AdminBorrowService {
+    fun searchBorrows(query: String): Result<Any?>
+}

src/main/kotlin/com/msksbr/bookmgr/service/AuthService.kt

@@ -1,6 +1,6 @@
 package com.msksbr.bookmgr.service
 
-import com.msksbr.bookmgr.dto.UserLoginDTO
+import com.msksbr.bookmgr.dto.UserLoginDto
 import com.msksbr.bookmgr.entity.User
 
 /*
@@ -13,5 +13,5 @@ interface AuthService {
     * @param loginDTO 包含 username 和 password 的请求体
     * @return 验证成功返回对应的 User 实体，失败返回 null
     */
-    fun login(loginDTO: UserLoginDTO): User?
+    fun login(loginDTO: UserLoginDto): User?
 }

src/main/kotlin/com/msksbr/bookmgr/service/BorrowService.kt

@@ -0,0 +1,9 @@
+package com.msksbr.bookmgr.service
+
+interface BorrowService {
+    fun getAllMyBorrows(userId: Long): Result<Any?>
+    fun searchMyBorrows(query: String): Result<Any?>
+    fun getOneBorrow(borrowId: Long): Result<Any?>
+    fun borrowBook(bookId: Long): Result<Any?>
+    fun returnBook(borrowId: Long): Result<Any?>
+}

src/main/kotlin/com/msksbr/bookmgr/service/impl/AuthServiceImpl.kt

@@ -1,7 +1,7 @@
 package com.msksbr.bookmgr.service.impl
 
 import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper
-import com.msksbr.bookmgr.dto.UserLoginDTO
+import com.msksbr.bookmgr.dto.UserLoginDto
 import com.msksbr.bookmgr.entity.User
 import com.msksbr.bookmgr.mapper.UserMapper
 import com.msksbr.bookmgr.service.AuthService
@@ -29,7 +29,7 @@ class AuthServiceImpl(
     * @param loginDTO 包含 username 和 password
     * @return 验证成功返回 User，失败返回 null
     */
-    override fun login(loginDTO: UserLoginDTO): User? {
+    override fun login(loginDTO: UserLoginDto): User? {
         val user = userMapper.selectOne(
             QueryWrapper<User>()
                 .eq("username", loginDTO.username)

src/main/kotlin/com/msksbr/bookmgr/service/impl/DashBoardServiceImpl.kt

@@ -30,6 +30,7 @@ class DashBoardServiceImpl(
         return Result.success(bookJsonList)
     }
 
+    // @TODO: 改成返回BorrowInfoDto
     override fun getAllBorrowRecords(): Result<Any?> {
         val borrowRecordList = borrowRecordMapper.selectList(null)
         val borrowRecordJsonList = borrowRecordList.map { borrowRecord ->