alternate buffer support (#12471)

schemas/settings.schema.json

@@ -275,6 +275,13 @@
           "default": false,
           "type": "boolean"
         },
+        "useAlternateBuffer": {
+          "title": "Use Alternate Screen Buffer",
+          "description": "Use an alternate screen buffer for the UI, preserving shell history.",
+          "markdownDescription": "Use an alternate screen buffer for the UI, preserving shell history.\n\n- Category: `UI`\n- Requires restart: `yes`\n- Default: `false`",
+          "default": false,
+          "type": "boolean"
+        },
         "customWittyPhrases": {
           "title": "Custom Witty Phrases",
           "description": "Custom witty phrases to display during loading. When provided, the CLI cycles through these instead of the defaults.",