Add free-type spell checker for students

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

package-lock.json

@@ -9,9 +9,11 @@
       "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
+        "dictionary-en": "^4.0.0",
         "express": "^5.1.0",
         "mammoth": "^1.12.0",
-        "multer": "^2.2.0"
+        "multer": "^2.2.0",
+        "nspell": "^2.1.5"
       },
       "engines": {
         "node": ">=24"
@@ -273,6 +275,16 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/dictionary-en": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/dictionary-en/-/dictionary-en-4.0.0.tgz",
+      "integrity": "sha512-3NHnE1uq33ZE/CIwaZ6gqxa4BnglHnxeAcTM0GJ7cmtRGcvX9InMK/IqLtYcUMFCUpUNgybH+DzkqdgAo3F1zg==",
+      "license": "(MIT AND BSD)",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/wooorm"
+      }
+    },
     "node_modules/dingbat-to-unicode": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/dingbat-to-unicode/-/dingbat-to-unicode-1.0.1.tgz",
@@ -583,6 +595,29 @@
         "node": ">= 0.10"
       }
     },
+    "node_modules/is-buffer": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/is-buffer/-/is-buffer-2.0.5.tgz",
+      "integrity": "sha512-i2R6zNFDwgEHJyQUtJEk0XFi1i0dPFn/oqjK3/vPCcDeJvW5NQ83V8QbicfF1SupOaB0h8ntgBC2YiE7dfyctQ==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/feross"
+        },
+        {
+          "type": "patreon",
+          "url": "https://www.patreon.com/feross"
+        },
+        {
+          "type": "consulting",
+          "url": "https://feross.org/support"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4"
+      }
+    },
     "node_modules/is-promise": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/is-promise/-/is-promise-4.0.0.tgz",
@@ -783,6 +818,15 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/nspell": {
+      "version": "2.1.5",
+      "resolved": "https://registry.npmjs.org/nspell/-/nspell-2.1.5.tgz",
+      "integrity": "sha512-PSStyugKMiD9mHmqI/CR5xXrSIGejUXPlo88FBRq5Og1kO5QwQ5Ilu8D8O5I/SHpoS+mibpw6uKA8rd3vXd2Sg==",
+      "license": "MIT",
+      "dependencies": {
+        "is-buffer": "^2.0.0"
+      }
+    },
     "node_modules/object-inspect": {
       "version": "1.13.4",
       "resolved": "https://registry.npmjs.org/object-inspect/-/object-inspect-1.13.4.tgz",