Restore accidentally removed files, a few additional import/calculation fixes

inventory-server/auth/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "inventory-auth-server",
+  "version": "1.0.0",
+  "description": "Authentication server for inventory management system",
+  "main": "server.js",
+  "scripts": {
+    "start": "node server.js"
+  },
+  "dependencies": {
+    "bcrypt": "^5.1.1",
+    "cors": "^2.8.5",
+    "dotenv": "^16.4.7",
+    "express": "^4.18.2",
+    "inquirer": "^8.2.6",
+    "jsonwebtoken": "^9.0.2",
+    "morgan": "^1.10.0",
+    "pg": "^8.11.3"
+  }
+}