add diff-match-patch

package-lock.json

@@ -16,6 +16,7 @@
         "body-parser": "^1.20.3",
         "classnames": "^2.5.1",
         "cookie-parser": "^1.4.7",
+        "diff-match-patch": "^1.0.5",
         "dotenv": "^16.4.7",
         "express": "^4.21.2",
         "react": "^19.0.0",
@@ -2719,6 +2720,12 @@
         "url": "https://github.com/sponsors/wooorm"
       }
     },
+    "node_modules/diff-match-patch": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/diff-match-patch/-/diff-match-patch-1.0.5.tgz",
+      "integrity": "sha512-IayShXAgj/QMXgB0IWmKx+rOPuGMhqm5w6jvFxmVenXKIzRqTAAsbBPT3kWQeGANj3jGgvcvv4yK6SxqYmikgw==",
+      "license": "Apache-2.0"
+    },
     "node_modules/dotenv": {
       "version": "16.4.7",
       "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.4.7.tgz",

package.json

@@ -19,6 +19,7 @@
     "body-parser": "^1.20.3",
     "classnames": "^2.5.1",
     "cookie-parser": "^1.4.7",
+    "diff-match-patch": "^1.0.5",
     "dotenv": "^16.4.7",
     "express": "^4.21.2",
     "react": "^19.0.0",