feat: добавить Image Gateway с кешем Souin

- добавлена сборка Caddy с Souin, Otter и NutsDB

- добавлена конфигурация dev, prod и test Docker Compose

- настроено кеширование через Otter L1 и NutsDB L2

- добавлены e2e-тесты Bun для кеша, restart и purge

- добавлена документация по запуску, API кеша и тестам

docker-compose.test.yml

@@ -0,0 +1,71 @@
+services:
+  fixture:
+    image: oven/bun:1
+    working_dir: /app
+    command: ["bun", "tests/fixture/server.js"]
+    volumes:
+      - .:/app:ro
+    networks:
+      - gateway-test
+
+  imgproxy:
+    image: darthsim/imgproxy:latest
+    environment:
+      GODEBUG: http2client=0
+      IMGPROXY_WORKERS: 2
+      IMGPROXY_MAX_SRC_RESOLUTION: 20
+      IMGPROXY_USE_ETAG: "true"
+      IMGPROXY_ENABLE_VIDEO_THUMBNAILS: "false"
+      IMGPROXY_DOWNLOAD_TIMEOUT: 30
+      IMGPROXY_ALLOWED_SOURCES: ""
+      NO_PROXY: localhost,127.0.0.1,fixture,caddy,imgproxy
+    depends_on:
+      fixture:
+        condition: service_started
+    networks:
+      - gateway-test
+
+  caddy:
+    build:
+      context: .
+      dockerfile: Dockerfile.caddy
+    volumes:
+      - ./Caddyfile:/etc/caddy/Caddyfile:ro
+      - caddy-data:/data
+      - caddy-cache:/cache
+    environment:
+      IMGPROXY_UPSTREAM: imgproxy:8080
+      DOMAIN: ""
+      CADDY_PORT: 8888
+      ADMIN_USER: admin
+      ADMIN_PASS: ""
+    depends_on:
+      imgproxy:
+        condition: service_started
+    networks:
+      - gateway-test
+
+  tester:
+    image: oven/bun:1
+    working_dir: /app
+    volumes:
+      - .:/app:ro
+    environment:
+      GATEWAY_URL: http://caddy:8888
+      ADMIN_URL: http://caddy:2019
+      SOURCE_IMAGE_URL: http://fixture:8080/image.png
+    depends_on:
+      caddy:
+        condition: service_started
+      fixture:
+        condition: service_started
+    networks:
+      - gateway-test
+
+networks:
+  gateway-test:
+    driver: bridge
+
+volumes:
+  caddy-data:
+  caddy-cache: