Fix test expectation for fs.readFile call count in agent-service.test.ts

The test "should reuse existing session if already started" expected fs.readFile to be called 1 time, but startConversation calls it 2 times on first call (loadSession + loadMetadata). The second call correctly reuses the in-memory session.

Co-authored-by: GTheMachine <156854865+GTheMachine@users.noreply.github.com>

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

@@ -103,8 +103,9 @@ describe("agent-service.ts", () => {
       });
 
       expect(result.success).toBe(true);
-      // Should only read file once
-      expect(fs.readFile).toHaveBeenCalledTimes(1);
+      // First call reads session file and metadata file (2 calls)
+      // Second call should reuse in-memory session (no additional calls)
+      expect(fs.readFile).toHaveBeenCalledTimes(2);
     });
   });