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>

frontend-electron/js/common/language.js

@@ -0,0 +1,56 @@
+// 多语言支持模块
+
+/**
+ * 多语言切换
+ */
+function langua_ge(lan = 'zh') {
+    $("[language='m']").each(function (i) {
+        $(this).html($(this).attr(lan));
+    });
+
+    $("[language='t']").each(function (i) {
+        $(this).attr("title", $(this).attr(lan));
+    });
+}
+
+/**
+ * 多语言字符串获取
+ * @param {string} str - 字符串键
+ * @param {string} s_lan - 当前语言 ('zh', 'ozh', 'en')
+ */
+function language_str(str, s_lan) {
+    let t = {
+        "whetherSave": { zh: "是否保存当前文件？", ozh: "是否保存當前文件？", en: "Do you want to save the current file?" },
+        "save": { zh: "保存", ozh: "保存", en: "Save" },
+        "noSave": { zh: "不保存", ozh: "不保存", en: "No saving" },
+        "cancel": { zh: "取消", ozh: "取消", en: "Cancel" },
+        "saveSucc": { zh: "保存成功至", ozh: "保存成功至", en: "Save successfully to" },
+        "saveFile": { zh: "保存文件", ozh: "保存文件", en: "Save file" },
+        "display": { zh: "预览", ozh: "預覽", en: "Display" },
+        "output": { zh: "导出", ozh: "導出", en: "Export" },
+        "bg": { zh: "背景", ozh: "背景", en: "Background" },
+        "selectPic": { zh: "请选择图片", ozh: "請選擇圖片", en: "Please select a picture" },
+        "img": { zh: "圖片", ozh: "圖片", en: "Image" },
+        "simg": { zh: "合成圖片", ozh: "合成圖片", en: "Synthesized Image" },
+        "text": { zh: "文本", ozh: "文本", en: "Text" },
+        "ctext": { zh: "圆形文本", ozh: "圆形文本", en: "Circle Text" },
+        "stext": { zh: "合成文本", ozh: "合成文本", en: "Synthesized Text" },
+        "rect": { zh: "矩形", ozh: "矩形", en: "Rectangle" },
+        "circ": { zh: "圓形", ozh: "圓形", en: "Circle" },
+        "line": { zh: "直線", ozh: "直線", en: "Line" },
+        "qrc": { zh: "二維碼", ozh: "二維碼", en: "QR code" },
+        "barc": { zh: "條形碼", ozh: "條形碼", en: "Barcode" },
+        "counter": { zh: "計數器", ozh: "计数器", en: "Counter" },
+        "about": { zh: "关于Soon Design", ozh: "關於Soon Design", en: "About Soon Design" },
+        "vers": { zh: "版本", ozh: "版本", en: "Version" },
+        "comf": { zh: "确认", ozh: "確認", en: "Select" },
+        "copyright": { zh: "© 2022 cardsoon  Co., Ltd. All rights reserved.", ozh: "© 2022 cardsoon  Co., Ltd. All rights reserved.", en: "© 2022 cardsoon  Co., Ltd. All rights reserved." }
+    };
+    return t[str] ? t[str][s_lan] : str;
+}
+
+module.exports = {
+    langua_ge,
+    language_str
+};
+