fix(backend): create recording placeholders for legacy streams

Backend/routes/streams.ts

@@ -51,6 +51,8 @@ const listSchema = z.object({
   limit: z.coerce.number().int().min(1).max(100).default(25),
 });
 
+const shouldCreateRecordingPlaceholder = (): boolean => mediaMode === 'legacy' || streamRecordingEnabled;
+
 router.get('/me/list', requireDeviceAuth, async (req, res) => {
   const parsed = listSchema.safeParse(req.query);
 
@@ -339,6 +341,10 @@ router.post('/:streamSessionId/accept', requireDeviceAuth, async (req, res) => {
     return;
   }
 
+  if (shouldCreateRecordingPlaceholder()) {
+    await createRecordingForStream(updated.id);
+  }
+
   if (sfuService) {
     try {
       await sfuService.startSession({
@@ -698,7 +704,7 @@ router.post('/:streamSessionId/end', requireDeviceAuth, async (req, res) => {
     }
   }
 
-  if (streamRecordingEnabled) {
+  if (shouldCreateRecordingPlaceholder()) {
     await createRecordingForStream(session.id);
   }