Refactor Docker setup to integrate Web UI and streamline configuration

- Updated Dockerfile to build and embed the SvelteKit Web UI directly into the gateway image, eliminating the need for a separate web service.
- Modified .dockerignore to exclude unnecessary directories related to the web service.
- Adjusted config.compose.yaml to remove CORS settings for the web service, as the UI now shares the same origin as the API.
- Enhanced README.md to reflect the new single-port architecture for accessing both the Web UI and API.
- Removed the standalone web Dockerfile and updated related documentation for local development and build processes.

config.compose.yaml

@@ -4,10 +4,7 @@ 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"
+# UI отдаётся с того же порта, что и API (образ шлюза) — отдельный CORS для панели не нужен.
 servers:
   - alias: main_srv
     base_url: http://host.docker.internal:9091