Bump @a2ui/markdown-it from 0.0.3 to 0.0.4 in /client/web

Bumps [@a2ui/markdown-it](https://github.com/google/A2UI/tree/HEAD/renderers/markdown/markdown-it) from 0.0.3 to 0.0.4.
- [Changelog](https://github.com/google/A2UI/blob/main/renderers/markdown/markdown-it/CHANGELOG.md)
- [Commits](https://github.com/google/A2UI/commits/HEAD/renderers/markdown/markdown-it)

---
updated-dependencies:
- dependency-name: "@a2ui/markdown-it"
  dependency-version: 0.0.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

client/web/package-lock.json

@@ -74,7 +74,7 @@
   "dependencies": {
     "@a2a-js/sdk": "^0.3.8",
     "@a2ui/lit": "^0.9.3",
-    "@a2ui/markdown-it": "^0.0.3",
+    "@a2ui/markdown-it": "^0.0.4",
     "@lit-labs/signals": "^0.1.3",
     "@lit/context": "^1.1.4",
     "lit": "^3.3.1",