feat(streams): add phase-1 single-server SFU session and transport APIs

Backend/routes/ops.ts

@@ -17,6 +17,7 @@ router.get('/ready', async (_req, res) => {
   try {
     await db.execute('select 1');
     await minioClient.bucketExists(minioBucket);
+    const sfuSessions = sfuService ? await sfuService.listSessions() : [];
 
     res.json({
       status: 'ready',
@@ -26,6 +27,7 @@ router.get('/ready', async (_req, res) => {
         mediaMode: mediaConfig.mode,
         mediaProvider: mediaProvider.name,
         sfuService: sfuService ? sfuService.mode : 'disabled',
+        sfuActiveSessions: sfuSessions.filter((session) => session.state !== 'ended').length,
       },
       timestamp: new Date().toISOString(),
     });