refactor(backend): move user routes to a module; add packages for cross-spawn types

package-lock.json

@@ -80,6 +80,7 @@
         "@types/bcrypt": "^6.0.0",
         "@types/better-sqlite3": "^7.6.13",
         "@types/cors": "^2.8.19",
+        "@types/cross-spawn": "^6.0.6",
         "@types/express": "^5.0.3",
         "@types/jsonwebtoken": "^9.0.10",
         "@types/node": "^22.19.7",
@@ -3791,6 +3792,16 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/cross-spawn": {
+      "version": "6.0.6",
+      "resolved": "https://registry.npmjs.org/@types/cross-spawn/-/cross-spawn-6.0.6.tgz",
+      "integrity": "sha512-fXRhhUkG4H3TQk5dBhQ7m/JDdSNHKwR2BBia62lhwEIq9xGiQKLxd6LymNhn47SjXhsUEPmxi+PKw2OkW4LLjA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/debug": {
       "version": "4.1.12",
       "resolved": "https://registry.npmjs.org/@types/debug/-/debug-4.1.12.tgz",