switch to codemirror

playground/package.json

@@ -9,12 +9,16 @@
     "preview": "vite preview"
   },
   "devDependencies": {
+    "@codemirror/theme-one-dark": "^6.1.2",
+    "@lezer/generator": "^1.7.3",
+    "@lezer/lr": "^1.4.2",
     "esbuild": "^0.25.0",
     "typescript": "~5.6.2",
     "vite": "^6.1.0"
   },
   "dependencies": {
     "@preact/signals": "^1.3.0",
+    "codemirror": "^6.0.1",
     "monaco-editor": "^0.52.0",
     "preact": "^10.24.3"
   }