add new endpoint /by-match/{matchId}

src/main/java/com/codzilla/backend/judge/problem/ProblemController.java

@@ -33,6 +33,24 @@ public class ProblemController {
     private final SqlServiceClient sqlServiceClient;
     private final MatchService matchService;
 
+    @GetMapping("/by-match/{matchId}")
+    public ResponseEntity<ProblemInfoDTO> getProblemByMatch(@PathVariable UUID matchId) {
+        Match match = matchService.getMatchById(matchId);
+        if (match == null || match.getProblem() == null) {
+            return ResponseEntity.notFound().build();
+        }
+        Problem problem = match.getProblem();
+
+        ProblemInfoDTO dto = new ProblemInfoDTO();
+        dto.setId(problem.getId());
+        dto.setName(problem.getName());
+        dto.setExternalId(problem.getExternalId());
+        dto.setType(problem.getType().name());
+        dto.setLevel(problem.getLevel() != null ? problem.getLevel().name() : "EASY");
+
+        return ResponseEntity.ok(dto);
+    }
+
     @PostMapping("/algo")
     public ResponseEntity<Problem> createAlgoProblem(
             @RequestBody CreateAlgoProblemRequest request) {

src/main/java/com/codzilla/backend/judge/problem/ProblemInfoDTO.java

@@ -0,0 +1,12 @@
+package com.codzilla.backend.judge.problem;
+
+import lombok.Data;
+
+@Data
+public class ProblemInfoDTO {
+    private Long id;
+    private String name;
+    private Long externalId;
+    private String type;
+    private String level;
+}