Replace Unit configuration with Nginx + PHP-FPM setup in Docker

- Remove outdated Unit-based Docker configuration and scripts.
- Introduce Nginx + PHP-FPM stack with environment-based configurations.
- Add custom Nginx setup for frontend-backend routing.
- Update Dockerfiles, Docker Compose, and related scripts for new architecture.

app/docker/web/Dockerfile

@@ -0,0 +1,31 @@
+FROM docker.io/nginx:1.31-alpine AS build
+
+COPY docker/web/conf/default.conf.template /etc/nginx/templates/default.conf.template
+COPY docker/web/conf/fastcgi_params /etc/nginx/fastcgi_params
+COPY docker/web/start.sh /usr/local/bin/start
+
+RUN chmod 755 /usr/local/bin/start
+
+FROM build AS app_build_for_production
+
+WORKDIR /home/app
+COPY application /home/app
+
+RUN apk --no-cache add git nodejs npm \
+    && npm install && npm run build \
+    && rm -rf /home/app/node_modules
+
+FROM build AS production
+
+COPY --from=app_build_for_production /home/app/public /usr/share/nginx/html
+
+WORKDIR /usr/share/nginx/html
+
+EXPOSE 80
+CMD ["/usr/local/bin/start"]
+
+FROM build AS develop
+WORKDIR /usr/share/nginx/html
+
+EXPOSE 80
+CMD ["/usr/local/bin/start"]