feat: add endpoint to fetch indexed session metadata and implement corresponding service method

server/src/modules/ai-runtime/ai-runtime.routes.ts

@@ -492,6 +492,18 @@ router.get(
   }),
 );
 
+/**
+ * Returns one DB-indexed session metadata row.
+ */
+router.get(
+  '/sessions/:sessionId',
+  asyncHandler(async (req: Request, res: Response) => {
+    const sessionId = readPathParam(req.params.sessionId, 'sessionId');
+    const session = llmSessionsService.getIndexedSession(sessionId);
+    res.json(createApiSuccessResponse({ session }));
+  }),
+);
+
 /**
  * Triggers provider disk scans and refreshes the shared sessions table.
  */