fix(menu): shorten the Close Pane / Tab menu label to Close

The right-click menu and the File menu sit next to Split / New Tab items,
so the surrounding context already says what closes; plain "Close" (⌘W)
matches the macOS convention. The palette and Keybindings page keep the
full name, where there is no surrounding menu to disambiguate.

src/ui/i18n/en.rs

@@ -1769,7 +1769,7 @@ pub fn translate_en(key: L10nKey) -> &'static str {
         L10nKey::AppMenuCopyWorkingDirectory => "Copy Working Directory",
         L10nKey::AppMenuCopySessionId => "Copy Session ID",
         L10nKey::AppMenuForkSession => "Fork Session",
-        L10nKey::AppMenuClosePaneTab => "Close Pane / Tab",
+        L10nKey::AppMenuClosePaneTab => "Close",
         L10nKey::AppMenuCloseOtherTabs => "Close Other Tabs",
         L10nKey::AppMenuCloseTabsRight => "Close Tabs to the Right",
         L10nKey::AppMenuReopenClosedTab => "Reopen Closed Tab",

src/ui/i18n/ja.rs

@@ -1846,7 +1846,7 @@ pub fn translate_ja(key: L10nKey) -> Option<&'static str> {
         L10nKey::AppMenuCopyWorkingDirectory => "作業ディレクトリをコピー",
         L10nKey::AppMenuCopySessionId => "セッション ID をコピー",
         L10nKey::AppMenuForkSession => "セッションをフォーク",
-        L10nKey::AppMenuClosePaneTab => "ペイン / タブを閉じる",
+        L10nKey::AppMenuClosePaneTab => "閉じる",
         L10nKey::AppMenuCloseOtherTabs => "他のタブを閉じる",
         L10nKey::AppMenuCloseTabsRight => "右側のタブを閉じる",
         L10nKey::AppMenuReopenClosedTab => "閉じたタブをもう一度開く",

src/ui/i18n/zh.rs

@@ -1671,7 +1671,7 @@ pub fn translate_zh(key: L10nKey) -> Option<&'static str> {
         L10nKey::AppMenuCopyWorkingDirectory => "复制工作目录",
         L10nKey::AppMenuCopySessionId => "复制会话 ID",
         L10nKey::AppMenuForkSession => "Fork 会话",
-        L10nKey::AppMenuClosePaneTab => "关闭窗格 / 标签页",
+        L10nKey::AppMenuClosePaneTab => "关闭",
         L10nKey::AppMenuCloseOtherTabs => "关闭其他标签页",
         L10nKey::AppMenuCloseTabsRight => "关闭右侧标签页",
         L10nKey::AppMenuReopenClosedTab => "重新打开已关闭的标签页",