fix(ui): render markdown in chat

ui/package.json

@@ -9,7 +9,9 @@
     "test": "vitest run --config vitest.config.ts"
   },
   "dependencies": {
-    "lit": "^3.3.2"
+    "dompurify": "^3.3.1",
+    "lit": "^3.3.2",
+    "marked": "^17.0.1"
   },
   "devDependencies": {
     "@vitest/browser-playwright": "4.0.16",