refactor: move docker-compose files to deploy/ directory structure

Reorganize Docker configuration into environment-specific directories:
- deploy/dev/: Development with hot reload and source mounting
- deploy/test/: Ephemeral testing with branch isolation and dynamic ports
- deploy/prod/: Production with resource limits, logging, and restart policy

Key improvements in test compose:
- Dynamic ports (no fixed 3000/8484) for parallel test runs
- Branch-isolated container/network names via TEST_INSTANCE_ID
- service_healthy condition instead of service_started
- Increased retry counts for stability

deploy/prod/.env.example

@@ -0,0 +1,3 @@
+PORT=3000
+GRIST_MCP_TOKEN=your-production-token
+CONFIG_PATH=/app/config.yaml

deploy/prod/docker-compose.yml

@@ -0,0 +1,31 @@
+# Production environment - resource limits, logging, restart policy
+services:
+  grist-mcp:
+    build:
+      context: ../..
+      dockerfile: Dockerfile
+    ports:
+      - "${PORT:-3000}:3000"
+    volumes:
+      - ./config.yaml:/app/config.yaml:ro
+    env_file:
+      - .env
+    restart: unless-stopped
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+          cpus: "1"
+        reservations:
+          memory: 128M
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "50m"
+        max-file: "5"
+    healthcheck:
+      test: ["CMD", "python", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:3000/health')"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 60s