Implement Phase 1: LangGraph backend MVP

Sets up the full backend foundation for CouncilOS:

- CouncilState TypedDict with all required fields and LangGraph reducers
- Three agent nodes: master_agent (drafts), critic_agent (scores + routes),
  writer_agent (final polish)
- LangGraph graph with cyclic rework loop: Master → Critic → (score < 8:
  back to Master | score ≥ 8: Writer → END)
- Safety valve: MAX_ITERATIONS=5 prevents infinite loops
- FastAPI app with REST endpoints (POST /api/councils/run, GET /api/councils/run/{id})
  and WebSocket endpoint (/ws/council/{run_id}) for real-time agent status events
- In-memory RunStore for Phase 1 (PostgreSQL-backed in Phase 3)
- pytest test suite: state, routing logic, critic parser, agent nodes, API endpoints
- .env.example, .gitignore, docker-compose.yml, Dockerfile

https://claude.ai/code/session_01RfMpt3TbMjZEtK3CAyP5iQ

backend/tests/test_api.py

@@ -0,0 +1,99 @@
+"""
+Integration tests for the FastAPI REST endpoints.
+
+Uses httpx.AsyncClient with the TestClient pattern — no real LLM calls.
+"""
+
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+import pytest
+from unittest.mock import AsyncMock, patch
+from fastapi.testclient import TestClient
+
+from main import app
+from api.run_store import run_store
+
+
+@pytest.fixture(autouse=True)
+def clean_run_store():
+    """Reset the run store before each test."""
+    run_store._store.clear()
+    yield
+    run_store._store.clear()
+
+
+client = TestClient(app)
+
+
+class TestHealthEndpoint:
+    def test_health_check_returns_ok(self):
+        response = client.get("/api/health")
+        assert response.status_code == 200
+        assert response.json()["status"] == "ok"
+
+
+class TestStartCouncilRun:
+    def test_start_run_returns_202_with_run_id(self):
+        with patch("api.routes._execute_run", new_callable=AsyncMock):
+            response = client.post(
+                "/api/councils/run",
+                json={"input_topic": "Erkläre maschinelles Lernen"},
+            )
+        assert response.status_code == 202
+        data = response.json()
+        assert "run_id" in data
+        assert data["status"] == "pending"
+        assert len(data["run_id"]) == 36  # UUID format
+
+    def test_start_run_rejects_empty_topic(self):
+        response = client.post("/api/councils/run", json={"input_topic": ""})
+        assert response.status_code == 422  # Pydantic validation error
+
+    def test_start_run_rejects_missing_topic(self):
+        response = client.post("/api/councils/run", json={})
+        assert response.status_code == 422
+
+
+class TestGetCouncilResult:
+    def test_get_pending_run(self):
+        run_store.create("test-run-id", "Test topic")
+        response = client.get("/api/councils/run/test-run-id")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["run_id"] == "test-run-id"
+        assert data["status"] == "pending"
+
+    def test_get_completed_run(self):
+        run_store.create("completed-run", "Topic")
+        run_store.update("completed-run", {
+            "status": "completed",
+            "final_draft": "Final polished document.",
+            "critic_score": 9.0,
+            "iteration_count": 2,
+        })
+        response = client.get("/api/councils/run/completed-run")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "completed"
+        assert data["final_draft"] == "Final polished document."
+        assert data["critic_score"] == 9.0
+        assert data["iteration_count"] == 2
+
+    def test_get_nonexistent_run_returns_404(self):
+        response = client.get("/api/councils/run/does-not-exist")
+        assert response.status_code == 404
+
+    def test_get_failed_run(self):
+        run_store.create("failed-run", "Topic")
+        run_store.update("failed-run", {
+            "status": "failed",
+            "error": "API connection timeout",
+        })
+        response = client.get("/api/councils/run/failed-run")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "failed"
+        assert "timeout" in data["error"]