feat(agent-office): GET /api/agent-office/nodes 엔드포인트

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019LV86jBozkNhSFXJA412fq

agent-office/tests/test_nodes_endpoint.py

@@ -0,0 +1,18 @@
+# agent-office/tests/test_nodes_endpoint.py
+import pytest
+from fastapi.testclient import TestClient
+
+@pytest.fixture
+def client(monkeypatch):
+    from app import main
+    async def fake_collect(redis=None):
+        return {"redis_ok": True, "paused": False, "paused_reason": None,
+                "generated_at": "2026-06-29T00:00:00Z", "workers": [], "links": []}
+    monkeypatch.setattr("app.node_monitor.collect_status", fake_collect)
+    return TestClient(main.app)
+
+def test_nodes_endpoint_returns_contract(client):
+    resp = client.get("/api/agent-office/nodes")
+    assert resp.status_code == 200
+    body = resp.json()
+    assert set(["redis_ok","paused","workers","links"]).issubset(body)