Require at least Positron 2025.6.0 (#736)

Author: juliasilge

apps/vscode/package.json

@@ -28,7 +28,8 @@
   ],
   "private": true,
   "engines": {
-    "vscode": "^1.75.0"
+    "vscode": "^1.75.0",
+    "positron": "^2025.6.0"
   },
   "main": "./out/main.js",
   "browser": "./browser.js",