feat: 支持Android端导出到Documents并多语言提示

Android端数据导出改为直接保存至Documents目录，导出成功后弹出带路径的多语言提示。引入@capacitor/status-bar与@capawesome/capacitor-file-picker依赖，主入口设置原生状态栏颜色与样式。各语言包补充导出成功带路径提示文案。

src/locales/en.ts

@@ -886,6 +886,7 @@ export default {
     export: 'Export',
     exporting: 'Exporting...',
     exportSuccess: 'Export successful',
+    exportSuccessWithPath: 'Export successful, file saved to: {path}',
     exportFailed: 'Export failed, please try again',
     importData: 'Import Data',
     importDataDesc: 'Restore game progress from JSON file',