Add CORS support and Docker configuration for web service

- Added CORS allowed origins in config.compose.yaml to enable cross-origin requests from the web service.
- Updated docker-compose.yml to include a new web service with build context and port mapping for local development.
- Enhanced gateway.go to support additional HTTP methods in CORS responses.
- Updated README.md to document the new web service and its configuration requirements.

config.compose.yaml

@@ -4,6 +4,10 @@ listen: ":8080"
 allow_all: true
 whitelist_cidrs: []
 trusted_proxies: []
+# UI в Docker (сервис web): браузер на другом origin — нужен CORS
+cors_allowed_origins:
+  - "http://127.0.0.1:4173"
+  - "http://localhost:4173"
 servers:
   - alias: main_srv
     base_url: http://host.docker.internal:9091