🌐 fix(i18n): add missing 'common.selected' translation key across all locales

- Add 'selected' key to common section in all language files (en-us, zh-cn, zh-tw, el-gr, es-es, fr-fr, ja-jp, pt-pt, ru-ru)
- Fix CLAUDE.md documentation to use correct 'yarn sync:i18n' command
- Resolve '[to be translated]' placeholders with proper localized translations
- Ensure consistency across all supported languages

Fixes missing i18n key error: [I18N] Missing key: common.selected

CLAUDE.md

@@ -25,7 +25,7 @@ This file provides guidance to AI coding assistants when working with code in th
 - **Development**: `yarn dev` - Runs Electron app in development mode with hot reload
 - **Debug**: `yarn debug` - Starts with debugging enabled, use `chrome://inspect` to attach debugger
 - **Build Check**: `yarn build:check` - **REQUIRED** before commits (lint + test + typecheck)
-  - If having i18n sort issues, run `yarn i18n:sync` first to sync template
+  - If having i18n sort issues, run `yarn sync:i18n` first to sync template
   - If having formatting issues, run `yarn format` first
 - **Test**: `yarn test` - Run all tests (Vitest) across main and renderer processes
 - **Single Test**:

src/renderer/src/i18n/locales/en-us.json

@@ -1021,6 +1021,7 @@
     "saved": "Saved",
     "search": "Search",
     "select": "Select",
+    "selected": "Selected",
     "selectedItems": "Selected {{count}} items",
     "selectedMessages": "Selected {{count}} messages",
     "settings": "Settings",

src/renderer/src/i18n/locales/zh-cn.json

@@ -1021,6 +1021,7 @@
     "saved": "已保存",
     "search": "搜索",
     "select": "选择",
+    "selected": "已选择",
     "selectedItems": "已选择 {{count}} 项",
     "selectedMessages": "选中 {{count}} 条消息",
     "settings": "设置",

src/renderer/src/i18n/locales/zh-tw.json

@@ -1021,6 +1021,7 @@
     "saved": "已儲存",
     "search": "搜尋",
     "select": "選擇",
+    "selected": "已選擇",
     "selectedItems": "已選擇 {{count}} 項",
     "selectedMessages": "選中 {{count}} 條訊息",
     "settings": "設定",

src/renderer/src/i18n/translate/el-gr.json

@@ -1021,6 +1021,7 @@
     "saved": "Αποθηκεύτηκε",
     "search": "Αναζήτηση",
     "select": "Επιλογή",
+    "selected": "Επιλεγμένο",
     "selectedItems": "Επιλέχθηκαν {{count}} αντικείμενα",
     "selectedMessages": "Επιλέχθηκαν {{count}} μηνύματα",
     "settings": "Ρυθμίσεις",

src/renderer/src/i18n/translate/es-es.json

@@ -1021,6 +1021,7 @@
     "saved": "Guardado",
     "search": "Buscar",
     "select": "Seleccionar",
+    "selected": "Seleccionado",
     "selectedItems": "{{count}} elementos seleccionados",
     "selectedMessages": "{{count}} mensajes seleccionados",
     "settings": "Configuración",

src/renderer/src/i18n/translate/fr-fr.json

@@ -1021,6 +1021,7 @@
     "saved": "enregistré",
     "search": "Rechercher",
     "select": "Sélectionner",
+    "selected": "Sélectionné",
     "selectedItems": "{{count}} éléments sélectionnés",
     "selectedMessages": "{{count}} messages sélectionnés",
     "settings": "Paramètres",

src/renderer/src/i18n/translate/ja-jp.json

@@ -1021,6 +1021,7 @@
     "saved": "保存されました",
     "search": "検索",
     "select": "選択",
+    "selected": "選択済み",
     "selectedItems": "{{count}}件の項目を選択しました",
     "selectedMessages": "{{count}}件のメッセージを選択しました",
     "settings": "設定",

src/renderer/src/i18n/translate/pt-pt.json

@@ -1021,6 +1021,7 @@
     "saved": "Guardado",
     "search": "Pesquisar",
     "select": "Selecionar",
+    "selected": "Selecionado",
     "selectedItems": "{{count}} itens selecionados",
     "selectedMessages": "{{count}} mensagens selecionadas",
     "settings": "Configurações",

src/renderer/src/i18n/translate/ru-ru.json

@@ -1021,6 +1021,7 @@
     "saved": "Сохранено",
     "search": "Поиск",
     "select": "Выбрать",
+    "selected": "Выбрано",
     "selectedItems": "Выбрано {{count}} элементов",
     "selectedMessages": "Выбрано {{count}} сообщений",
     "settings": "Настройки",