refactor: include problemTitle in response DTO (#166)

Author: thezz9

src/main/java/org/ezcode/codetest/application/submission/dto/response/submission/GroupedSubmissionResponse.java

@@ -13,13 +13,16 @@
 import lombok.Getter;
 
 @Getter
-@JsonPropertyOrder({"problemId", "problemDescription", "submissions"})
+@JsonPropertyOrder({"problemId", "problemTitle", "problemDescription", "submissions"})
 @Schema(description = "문제 단위로 묶은 제출 목록 응답")
 public class GroupedSubmissionResponse {
 
     @Schema(description = "문제 ID", example = "10")
     private final Long problemId;
 
+    @Schema(description = "문제 제목", example = "A + B")
+    private final String problemTitle;
+
     @Schema(description = "문제 설명", example = "두 수의 합을 구하는 문제입니다.")
     private final String problemDescription;
 
@@ -45,6 +48,7 @@ private static GroupedSubmissionResponse createSorted(Problem problem, List<Subm
 
     private GroupedSubmissionResponse(Problem problem, List<Submission> submissions) {
         this.problemId = problem.getId();
+        this.problemTitle = problem.getTitle();
         this.problemDescription = problem.getDescription();
         this.submissions = submissions.stream()
             .map(SubmissionDetailResponse::from)

src/main/java/org/ezcode/codetest/infrastructure/swagger/config/SwaggerConfig.java

@@ -14,7 +14,7 @@
 @OpenAPIDefinition(
 	servers = {
 		@Server(
-			url = "https://ezcode.my",           // ← 슬래시 없이 호스트만!
+			url = "http://localhost:8080",           // ← 슬래시 없이 호스트만!
 			description = "Production server"
 		)
 	},