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

docker-compose.yml

@@ -0,0 +1,54 @@
+version: "3.9"
+
+# CouncilOS — local development environment
+# Usage:
+#   docker compose up -d          # Start all services
+#   docker compose down           # Stop all services
+#   docker compose logs -f api    # Follow API logs
+
+services:
+  # ---------------------------------------------------------------------------
+  # PostgreSQL — stores council blueprints (used from Phase 2)
+  # ---------------------------------------------------------------------------
+  db:
+    image: postgres:16-alpine
+    restart: unless-stopped
+    environment:
+      POSTGRES_DB: councilOS
+      POSTGRES_USER: user
+      POSTGRES_PASSWORD: password
+    ports:
+      - "5432:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U user -d councilOS"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  # ---------------------------------------------------------------------------
+  # CouncilOS API — FastAPI + LangGraph backend
+  # ---------------------------------------------------------------------------
+  api:
+    build:
+      context: ./backend
+      dockerfile: Dockerfile
+    restart: unless-stopped
+    ports:
+      - "8000:8000"
+    env_file:
+      - .env
+    environment:
+      DATABASE_URL: postgresql+asyncpg://user:password@db:5432/councilOS
+    volumes:
+      - ./backend:/app
+      - chroma_data:/app/chroma_db
+    depends_on:
+      db:
+        condition: service_healthy
+    command: uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+
+volumes:
+  postgres_data:
+  chroma_data: