fix: Resolve Vercel build issues with Node.js v22 compatibility

- Added .nvmrc to force Node.js 18 for Vercel deployment
- Simplified vercel.json to minimal configuration
- Updated build scripts to avoid TypeScript compilation issues
- Fixed Rollup native module compatibility error
- Removed conflicting vercel.json files
- Enhanced environment variable documentation
- Updated repository remote to main RabbitDaCoder/ExpressLogistics

Author: techagbadev-create

client/.nvmrc

@@ -0,0 +1 @@
+18

client/package.json

@@ -7,6 +7,7 @@
     "dev": "vite",
     "build": "vite build",
     "build:tsc": "tsc -b && vite build",
+    "build:vercel": "vite build --mode production",
     "lint": "eslint .",
     "preview": "vite preview"
   },

client/vercel.json

@@ -0,0 +1,8 @@
+{
+  "rewrites": [
+    {
+      "source": "/(.*)",
+      "destination": "/index.html"
+    }
+  ]
+}