重构 monorepo 并完善网页端订阅与首页体验

- 迁移为 frontend-web、frontend-electron、backend-web 与 docker 部署结构
- 网页端：订阅门禁二次弹窗、套餐/支付组件化、顶栏分组对齐
- 首页：最近文件与模板库布局优化，缩略图对齐，下载与删除操作
- 新增管理后台、支付与云端文件 API，更新 README 与项目规范

Co-authored-by: Cursor <cursoragent@cursor.com>

docker/docker-compose.yml

@@ -0,0 +1,67 @@
+name: soondesign
+
+services:
+  mysql:
+    image: mysql:8.0
+    container_name: soondesign-mysql
+    restart: unless-stopped
+    environment:
+      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD:-rootlocal}
+      MYSQL_DATABASE: ${MYSQL_DATABASE:-soondesign}
+      MYSQL_USER: ${MYSQL_USER:-soondesign}
+      MYSQL_PASSWORD: ${MYSQL_PASSWORD:-soondesign}
+    command:
+      - --character-set-server=utf8mb4
+      - --collation-server=utf8mb4_unicode_ci
+    volumes:
+      - soondesign_mysql_data:/var/lib/mysql
+      - ../backend-web/schema.sql:/docker-entrypoint-initdb.d/01-schema.sql:ro
+    healthcheck:
+      test: ["CMD", "mysqladmin", "ping", "-h", "127.0.0.1", "-uroot", "-p${MYSQL_ROOT_PASSWORD:-rootlocal}"]
+      interval: 5s
+      timeout: 5s
+      retries: 30
+      start_period: 30s
+
+  api:
+    image: php:8.2-cli-bookworm
+    container_name: soondesign-api
+    restart: unless-stopped
+    ports:
+      - "${BACKEND_PORT:-8102}:8080"
+    environment:
+      SOON_DB_HOST: mysql
+      SOON_DB_PORT: 3306
+      SOON_DB_NAME: ${MYSQL_DATABASE:-soondesign}
+      SOON_DB_USER: ${MYSQL_USER:-soondesign}
+      SOON_DB_PASS: ${MYSQL_PASSWORD:-soondesign}
+      SOON_DEV_ADMIN_EMAIL: ${SOON_DEV_ADMIN_EMAIL:-admin@local.test}
+      SOON_DEV_ADMIN_PASS: ${SOON_DEV_ADMIN_PASS:-admin123}
+    volumes:
+      - ../backend-web:/var/www
+      - ./config/local.php:/var/www/config/local.php:ro
+      - ../soonModels:/var/soonModels
+      - ./php:/docker/php:ro
+    entrypoint: ["/bin/sh", "-c", "tr -d '\\r' < /docker/php/entrypoint-dev.sh | sh"]
+    depends_on:
+      mysql:
+        condition: service_healthy
+
+  frontend:
+    image: nginx:1.27-alpine
+    container_name: soondesign-frontend
+    restart: unless-stopped
+    ports:
+      - "${WEB_PORT:-8100}:8080"
+      - "${ELECTRON_PORT:-8101}:8081"
+    volumes:
+      - ../frontend-web:/var/www/web:ro
+      - ../frontend-electron:/var/www/electron:ro
+      - ./config/deploy-config.js:/var/www/web/assets/deploy-config.js:ro
+      - ./nginx/frontend.conf:/etc/nginx/conf.d/default.conf:ro
+    depends_on:
+      - api
+
+volumes:
+  soondesign_mysql_data:
+    name: soondesign_mysql_data