移动下载端改用共享核心包，与桌面端共用任务业务

- store 改由 createGalleryStore(variant:"mobile") 生成，保留“继续加载”交互
- 与桌面端共用同一份 API 解码、任务规范化、派生与排序实现
- 取消收藏不再因本地找不到 gid 抛 TypeError
- 删除重复的 taskSocket/progressiveImages/validate/thumbnail，改从共享包导入
- 远端搜索改用共享 fetchGalleries，翻页按游标转发
- main.js 按需注册 Element Plus，入口 JS 由约 1.13MB 降到约 486KB
- 依赖新增 file:../lionwebsite-frontend-shared

测试：12 项通过；构建成功，入口仍为 /asserts/mobile/index.js|css。

package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "axios": "^1.0.0",
         "element-plus": "^2.2.15",
+        "lionwebsite-frontend-shared": "file:../lionwebsite-frontend-shared",
         "qs": "^6.11.0",
         "vue": "^3.2.37",
         "vuex": "^4.0.2"
@@ -19,6 +20,9 @@
         "vite": "8.3.0"
       }
     },
+    "../lionwebsite-frontend-shared": {
+      "version": "1.0.0"
+    },
     "node_modules/@babel/helper-string-parser": {
       "version": "7.29.7",
       "resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.29.7.tgz",
@@ -1281,6 +1285,10 @@
         "url": "https://opencollective.com/parcel"
       }
     },
+    "node_modules/lionwebsite-frontend-shared": {
+      "resolved": "../lionwebsite-frontend-shared",
+      "link": true
+    },
     "node_modules/lodash": {
       "version": "4.18.1",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.18.1.tgz",