Use js-diff instead of diff-match-patch for word level diffs

web-app/package.json

@@ -19,7 +19,7 @@
     "@sveltejs/adapter-node": "5.2.12",
     "@sveltejs/kit": "2.20.2",
     "@sveltejs/vite-plugin-svelte": "5.0.3",
-    "@types/diff-match-patch": "1.0.36",
+    "@types/diff": "7.0.2",
     "@types/eslint": "9.6.1",
     "@types/eslint__js": "9.14.0",
     "@types/eslint-config-prettier": "6.11.3",
@@ -38,7 +38,7 @@
     "vite": "6.2.5"
   },
   "dependencies": {
-    "diff-match-patch": "1.0.5",
+    "diff": "7.0.0",
     "highlight.js": "11.11.1",
     "isomorphic-dompurify": "2.22.0",
     "marked": "15.0.7",