feat: region 관련 관리 기능 추가

src/main/java/com/example/solidconnection/admin/location/region/controller/AdminRegionController.java

@@ -0,0 +1,58 @@
+package com.example.solidconnection.admin.location.region.controller;
+
+import com.example.solidconnection.admin.location.region.dto.AdminRegionCreateRequest;
+import com.example.solidconnection.admin.location.region.dto.AdminRegionResponse;
+import com.example.solidconnection.admin.location.region.dto.AdminRegionUpdateRequest;
+import com.example.solidconnection.admin.location.region.service.AdminRegionService;
+import jakarta.validation.Valid;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RequiredArgsConstructor
+@RequestMapping("/admin/regions")
+@RestController
+public class AdminRegionController {
+
+    private final AdminRegionService adminRegionService;
+
+    @GetMapping
+    public ResponseEntity<List<AdminRegionResponse>> getAllRegions() {
+        List<AdminRegionResponse> responses = adminRegionService.getAllRegions();
+        return ResponseEntity.ok(responses);
+    }
+
+    @PostMapping
+    public ResponseEntity<AdminRegionResponse> createRegion(
+            @Valid @RequestBody AdminRegionCreateRequest request
+    ) {
+        AdminRegionResponse response = adminRegionService.createRegion(request);
+        return ResponseEntity.status(HttpStatus.CREATED).body(response);
+    }
+
+    @PutMapping("/{code}")
+    public ResponseEntity<AdminRegionResponse> updateRegion(
+            @PathVariable String code,
+            @Valid @RequestBody AdminRegionUpdateRequest request
+    ) {
+        AdminRegionResponse response = adminRegionService.updateRegion(code, request);
+        return ResponseEntity.ok(response);
+    }
+
+    @DeleteMapping("/{code}")
+    public ResponseEntity<Void> deleteRegion(
+            @PathVariable String code
+    ) {
+        adminRegionService.deleteRegion(code);
+        return ResponseEntity.noContent().build();
+    }
+}

src/main/java/com/example/solidconnection/admin/location/region/dto/AdminRegionCreateRequest.java

@@ -0,0 +1,16 @@
+package com.example.solidconnection.admin.location.region.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record AdminRegionCreateRequest(
+        @NotBlank(message = "지역 코드는 필수입니다")
+        @Size(min = 1, max = 10, message = "지역 코드는 1자 이상 10자 이하여야 합니다")
+        String code,
+
+        @NotBlank(message = "한글 지역명은 필수입니다")
+        @Size(min = 1, max = 100, message = "한글 지역명은 1자 이상 100자 이하여야 합니다")
+        String koreanName
+) {
+
+}

src/main/java/com/example/solidconnection/admin/location/region/dto/AdminRegionResponse.java

@@ -0,0 +1,14 @@
+package com.example.solidconnection.admin.location.region.dto;
+
+import com.example.solidconnection.location.region.domain.Region;
+
+public record AdminRegionResponse(
+        String code
+) {
+
+    public static AdminRegionResponse from(Region region) {
+        return new AdminRegionResponse(
+                region.getCode()
+        );
+    }
+}

src/main/java/com/example/solidconnection/admin/location/region/service/AdminRegionService.java

@@ -0,0 +1,72 @@
+package com.example.solidconnection.admin.location.region.service;
+
+import com.example.solidconnection.admin.location.region.dto.AdminRegionCreateRequest;
+import com.example.solidconnection.admin.location.region.dto.AdminRegionResponse;
+import com.example.solidconnection.admin.location.region.dto.AdminRegionUpdateRequest;
+import com.example.solidconnection.common.exception.CustomException;
+import com.example.solidconnection.common.exception.ErrorCode;
+import com.example.solidconnection.location.region.domain.Region;
+import com.example.solidconnection.location.region.repository.RegionRepository;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class AdminRegionService {
+
+    private final RegionRepository regionRepository;
+
+    @Transactional(readOnly = true)
+    public List<AdminRegionResponse> getAllRegions() {
+        return regionRepository.findAll()
+                .stream()
+                .map(AdminRegionResponse::from)
+                .toList();
+    }
+
+    @Transactional
+    public AdminRegionResponse createRegion(AdminRegionCreateRequest request) {
+        regionRepository.findById(request.code())
+                .ifPresent(region -> {
+                    throw new CustomException(ErrorCode.REGION_ALREADY_EXISTS);
+                });
+
+        regionRepository.findByKoreanName(request.koreanName())
+                .ifPresent(region -> {
+                    throw new CustomException(ErrorCode.REGION_ALREADY_EXISTS);
+                });
+
+        Region region = new Region(request.code(), request.koreanName());
+        Region savedRegion = regionRepository.save(region);
+
+        return AdminRegionResponse.from(savedRegion);
+    }
+
+    @Transactional
+    public AdminRegionResponse updateRegion(String code, AdminRegionUpdateRequest request) {
+        Region region = regionRepository.findById(code)
+                .orElseThrow(() -> new CustomException(ErrorCode.REGION_NOT_FOUND));
+
+        regionRepository.findByKoreanName(request.koreanName())
+                .ifPresent(existingRegion -> {
+                    if (!existingRegion.getCode().equals(code)) {
+                        throw new CustomException(ErrorCode.REGION_ALREADY_EXISTS);
+                    }
+                });
+
+        Region updatedRegion = new Region(region.getCode(), request.koreanName());
+        Region savedRegion = regionRepository.save(updatedRegion);
+
+        return AdminRegionResponse.from(savedRegion);
+    }
+
+    @Transactional
+    public void deleteRegion(String code) {
+        Region region = regionRepository.findById(code)
+                .orElseThrow(() -> new CustomException(ErrorCode.REGION_NOT_FOUND));
+
+        regionRepository.delete(region);
+    }
+}