fix: update test expectations for file read calls in agent-service

- Adjusted the test to reflect the addition of queue state file reading, increasing the expected number of file read calls from 2 to 3.
- Updated comments for clarity regarding the file reading process in the agent-service tests.

apps/server/tests/unit/services/agent-service.test.ts

@@ -106,9 +106,9 @@ describe('agent-service.ts', () => {
       });
 
       expect(result.success).toBe(true);
-      // First call reads session file and metadata file (2 calls)
+      // First call reads session file, metadata file, and queue state file (3 calls)
       // Second call should reuse in-memory session (no additional calls)
-      expect(fs.readFile).toHaveBeenCalledTimes(2);
+      expect(fs.readFile).toHaveBeenCalledTimes(3);
     });
   });