enhance rag retrieval + summary

backend/src/main/java/com/aiteacher/topic/TopicController.java

@@ -5,6 +5,7 @@ import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.UUID;
 
 @RestController
 @RequestMapping("/api/v1/topics")
@@ -32,4 +33,21 @@ public class TopicController {
         TopicSummaryResponse response = topicSummaryService.generateSummary(topic);
         return ResponseEntity.ok(response);
     }
+
+    @GetMapping("/{id}/summaries")
+    public ResponseEntity<List<SavedSummaryItem>> listSummaries(@PathVariable String id) {
+        topicRepository.findById(id)
+            .orElseThrow(() -> new NoSuchElementException("Topic not found."));
+
+        return ResponseEntity.ok(topicSummaryService.listSummaries(id));
+    }
+
+    @GetMapping("/{id}/summaries/{summaryId}")
+    public ResponseEntity<TopicSummaryResponse> getSummary(@PathVariable String id,
+                                                            @PathVariable UUID summaryId) {
+        topicRepository.findById(id)
+            .orElseThrow(() -> new NoSuchElementException("Topic not found."));
+
+        return ResponseEntity.ok(topicSummaryService.getSummary(summaryId));
+    }
 }