fix: Add missing @lezer/highlight dependency to agents-manage-ui

The codemirror-theme-duotone package requires @lezer/highlight as a peer dependency.
This was causing the build to fail on GitHub Actions.

Verified that tests pass locally after adding this dependency.

Author: amikofalvy

agents-manage-ui/package.json

@@ -39,6 +39,7 @@
     "@radix-ui/react-tooltip": "^1.2.7",
     "@sinclair/typebox": "^0.34.40",
     "@types/dagre": "^0.7.53",
+    "@lezer/highlight": "^1.2.1",
     "@uiw/codemirror-theme-duotone": "^4.25.1",
     "@uiw/react-codemirror": "^4.25.1",
     "@xyflow/react": "^12.8.2",