feat(web): type-aware install dialog + refresh sidebar after install

The marketplace install confirm dialog was hardcoded to "安装插件 / 确定要安装
插件 X 吗" for every type. Make it type-aware (plugin / MCP / skill) and show
more info: type chip, author/name id, and version when present.

Also refresh all sidebar extension lists (plugins, MCP servers, skills) when
an install task completes, so the newly-installed extension appears
immediately regardless of type (previously only refreshPlugins ran).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/i18n/locales/en-US.ts

@@ -1531,6 +1531,12 @@ const enUS = {
     },
   },
   addExtension: {
+    installTitle: 'Install {{type}}',
+    installConfirm: 'Install {{type}} "{{name}}"?',
+    installInfoType: 'Type',
+    installInfoId: 'ID',
+    installInfoVersion: 'Version',
+    installSuccess: 'Installed successfully',
     manualAdd: 'Manual Add',
     uploadExtension: 'Drag & drop or click to upload',
     uploadHint: 'Supports .zip (skills) and .lbpkg (plugins) files',

web/src/i18n/locales/zh-Hans.ts

@@ -1467,6 +1467,12 @@ const zhHans = {
     },
   },
   addExtension: {
+    installTitle: '安装{{type}}',
+    installConfirm: '确定要安装{{type}} "{{name}}" 吗？',
+    installInfoType: '类型',
+    installInfoId: '标识',
+    installInfoVersion: '版本',
+    installSuccess: '安装成功',
     manualAdd: '手动添加',
     uploadExtension: '拖拽或点击上传扩展包',
     uploadHint: '支持 .zip（技能）和 .lbpkg（插件）文件',