feat(sidebar): add group-by-type toggle to installed extensions section

- Add group-by-type button to extensions category header (mirrors the
  agent group-by-kind pattern) — syncs with the extensions page Switch
  via shared SidebarDataContext state
- Relocate both group and refresh controls to sit left-aligned
  immediately after the title for both Agent and Extensions sections
- Add plugins.groupByTypeShort i18n key to all 8 locales

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -540,6 +540,7 @@ const enUS = {
     kindBadgeAgent: 'Agent',
     kindBadgePipeline: 'Pipeline',
     groupByKind: 'Group by type',
+    groupByKindShort: 'Group',
     pipelineTypeDescription:
       'Keep the existing no-code message pipeline for backward compatibility. It only handles message events.',
     allEvents: 'Supports all EBA events',
@@ -602,6 +603,7 @@ const enUS = {
     noExtensionInstalled: 'No extensions installed',
     loadingExtensions: 'Loading extensions...',
     groupByType: 'Group by format',
+    groupByTypeShort: 'Group',
     pluginConfig: 'Plugin Configuration',
     pluginSort: 'Plugin Sort',
     pluginSortDescription:

web/src/i18n/locales/es-ES.ts

@@ -506,6 +506,7 @@ const esES = {
     noExtensionInstalled: 'No hay extensiones instaladas',
     loadingExtensions: 'Cargando extensiones...',
     groupByType: 'Agrupar por formato',
+    groupByTypeShort: 'Agrupar',
     pluginConfig: 'Configuración del plugin',
     pluginSort: 'Orden de plugins',
     pluginSortDescription:

web/src/i18n/locales/ja-JP.ts

@@ -524,6 +524,7 @@ const jaJP = {
     kindBadgeAgent: 'Agent',
     kindBadgePipeline: 'パイプライン',
     groupByKind: 'タイプ別にグループ化',
+    groupByKindShort: 'グループ',
     pipelineTypeDescription:
       '既存のノーコードメッセージ Pipeline を互換性のため保持します。メッセージイベントのみ処理できます。',
     allEvents: 'すべての EBA イベントに対応',
@@ -584,6 +585,7 @@ const jaJP = {
     noExtensionInstalled: '拡張機能がインストールされていません',
     loadingExtensions: '拡張機能を読み込み中...',
     groupByType: '形式でグループ化',
+    groupByTypeShort: 'グループ',
     pluginConfig: 'プラグイン設定',
     pluginSort: 'プラグインの並び替え',
     pluginSortDescription:

web/src/i18n/locales/ru-RU.ts

@@ -505,6 +505,7 @@ const ruRU = {
     noExtensionInstalled: 'Расширения не установлены',
     loadingExtensions: 'Загрузка расширений...',
     groupByType: 'Группировать по формату',
+    groupByTypeShort: 'Группа',
     pluginConfig: 'Настройка плагина',
     pluginSort: 'Порядок плагинов',
     pluginSortDescription:

web/src/i18n/locales/th-TH.ts

@@ -490,6 +490,7 @@ const thTH = {
     noExtensionInstalled: 'ยังไม่มีส่วนขยายที่ติดตั้ง',
     loadingExtensions: 'กำลังโหลดส่วนขยาย...',
     groupByType: 'จัดกลุ่มตามรูปแบบ',
+    groupByTypeShort: 'จัดกลุ่ม',
     pluginConfig: 'การกำหนดค่าปลั๊กอิน',
     pluginSort: 'เรียงลำดับปลั๊กอิน',
     pluginSortDescription:

web/src/i18n/locales/vi-VN.ts

@@ -500,6 +500,7 @@ const viVN = {
     noExtensionInstalled: 'Chưa cài đặt tiện ích mở rộng nào',
     loadingExtensions: 'Đang tải tiện ích mở rộng...',
     groupByType: 'Nhóm theo định dạng',
+    groupByTypeShort: 'Nhóm',
     pluginConfig: 'Cấu hình Plugin',
     pluginSort: 'Sắp xếp Plugin',
     pluginSortDescription:

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

@@ -519,6 +519,7 @@ const zhHans = {
     kindBadgeAgent: 'Agent',
     kindBadgePipeline: '流水线',
     groupByKind: '按类型分组',
+    groupByKindShort: '分组',
     pipelineTypeDescription:
       '保留现有无代码消息流水线，兼容旧配置，只能处理消息事件。',
     allEvents: '支持全部 EBA 事件',
@@ -578,6 +579,7 @@ const zhHans = {
     noExtensionInstalled: '暂未安装任何扩展',
     loadingExtensions: '正在加载扩展...',
     groupByType: '按格式分组',
+    groupByTypeShort: '分组',
     pluginSort: '插件排序',
     pluginSortDescription:
       '插件顺序会影响同一事件内的处理顺序，请拖动插件卡片排序',

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

@@ -476,6 +476,7 @@ const zhHant = {
     noExtensionInstalled: '暫未安裝任何擴充功能',
     loadingExtensions: '正在載入擴充功能...',
     groupByType: '依格式分組',
+    groupByTypeShort: '分組',
     pluginSort: '外掛排序',
     pluginSortDescription:
       '外掛順序會影響同一事件內的處理順序，請拖曳外掛卡片排序',