Fix prismjs DOM Clobbering vulnerability (Dependabot #45)

Add npm override in app/package.json to force prismjs ^1.30.0,
resolving the vulnerable 1.27.0 version nested under refractor 3.x
(transitive dep of react-syntax-highlighter).

Note: The remaining Dependabot alerts (pypdf #47-60, requests #46)
cannot be fixed here — they are pinned by upstream dependencies
(graphrag-sdk pins pypdf<6.0.0, multilspy pins requests==2.32.3).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: gkorland

app/package-lock.json

@@ -41,6 +41,9 @@
     "tailwindcss-animate": "^1.0.7",
     "vaul": "^1.1.2"
   },
+  "overrides": {
+    "prismjs": "^1.30.0"
+  },
   "devDependencies": {
     "@types/node": "^20.19.4",
     "@types/react": "^18.3.18",