Add package manifest pinning Express 5 and deps

package.json

@@ -0,0 +1,22 @@
+{
+  "name": "hidden-spectre-server",
+  "version": "1.0.0",
+  "description": "Backend for Hidden Spectre — AR ghost hunt (fan-made tribute, not affiliated with the LEGO Group)",
+  "type": "module",
+  "main": "server/index.js",
+  "scripts": {
+    "start": "node server/index.js",
+    "seed": "node server/seed.js"
+  },
+  "engines": {
+    "node": ">=18"
+  },
+  "dependencies": {
+    "express": "^5.2.1",
+    "better-sqlite3": "^11.8.1",
+    "bcryptjs": "^3.0.2",
+    "jsonwebtoken": "^9.0.2",
+    "multer": "^2.0.0",
+    "dotenv": "^16.4.7"
+  }
+}