fix(workspace): refine workbench defaults and cursor

Add Quick Commands as the default Workbench tab and update
the default three-column layout proportions to better match
the intended workspace design.

Also fix terminal hover cursor behavior and add locale and
docs updates for the new default interaction.

packages/frontend/src/locales/en-US.json

@@ -1281,6 +1281,7 @@
         "noSession": "No active session",
         "fileManagerHint": "Activate an SSH session to browse remote files.",
         "tabs": {
+          "quickCommands": "Quick Commands",
           "files": "Files",
           "history": "History",
           "editor": "Editor"

packages/frontend/src/locales/ja-JP.json

@@ -573,6 +573,7 @@
             "noSession": "アクティブなセッションはありません",
             "fileManagerHint": "SSH セッションを有効にするとリモートファイルを参照できます。",
             "tabs": {
+                "quickCommands": "クイックコマンド",
                 "files": "ファイル",
                 "history": "履歴",
                 "editor": "エディター"

packages/frontend/src/locales/zh-CN.json

@@ -1285,6 +1285,7 @@
         "noSession": "未激活会话",
         "fileManagerHint": "激活一个 SSH 会话后即可浏览远程文件。",
         "tabs": {
+          "quickCommands": "快捷指令",
           "files": "文件",
           "history": "历史命令",
           "editor": "编辑器"