Add Linux App Store Web Portal with Kubernetes deployment

- React-style static web portal with Tailwind CSS
- OS detection (Debian/Ubuntu, Fedora, Arch, Generic)
- Dynamic install commands (apt://, appstream://, flatpak)
- 9 pre-configured applications
- Kubernetes: 2 replicas, LoadBalancer service, Nginx ingress
- GitLab Container Registry (git.giaco.net/capitano/webapplinux)
- Namespace: linuxwebapp
- Added Dockerfile, nginx.conf, deploy.sh, docker-compose.yml
- Updated README.md with deployment instructions

Dockerfile.simple

@@ -0,0 +1,9 @@
+FROM nginx:alpine
+
+COPY frontend/ /usr/share/nginx/html/
+
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]