fix(call): defer LiveKit room teardown until after the call-ended commit

src/main/java/com/ssu/unithon/call/application/CallService.java

@@ -35,6 +35,8 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 
 @Service
 public class CallService {
@@ -174,7 +176,7 @@ public void terminate(UUID callId, String participantKey) {
         Call call = lockedCall(callId);
         if (call.getStatus() == CallStatus.ENDED) return;
         call.end(clock.instant());
-        closeLiveKitRoom(call);
+        afterCommit(() -> closeLiveKitRoom(call));
     }
 
     @Transactional(readOnly = true)
@@ -320,7 +322,7 @@ public void end(UUID callId, String creatorKey) {
         }
 
         call.end(clock.instant());
-        closeLiveKitRoom(call);
+        afterCommit(() -> closeLiveKitRoom(call));
     }
 
     @Transactional(readOnly = true)
@@ -345,6 +347,27 @@ private void cleanupStalePhoneCalls(String phoneNumber) {
         }
     }
 
+    /**
+     * Runs {@code action} only after this transaction commits. closeLiveKitRoom kicks the other
+     * participant's live LiveKit connection immediately (a real-time push, not a poll), which was
+     * racing the ENDED/REJECTED status write it's paired with: that write doesn't durably commit
+     * until the surrounding @Transactional method returns, so the kicked participant's client
+     * could poll /status right after being disconnected and still read the old ACTIVE status.
+     * Deferring to afterCommit makes the status change visible before the disconnect fires.
+     */
+    private void afterCommit(Runnable action) {
+        if (!TransactionSynchronizationManager.isSynchronizationActive()) {
+            action.run();
+            return;
+        }
+        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
+            @Override
+            public void afterCommit() {
+                action.run();
+            }
+        });
+    }
+
     private void closeLiveKitRoom(Call call) {
         for (ParticipantSlot slot : slots.findByCallId(call.getId())) {
             gateway.remove(call.getLivekitRoomName(), slot.getIdentity());