feat: implement merchant dashboard, secure auth, and short_id system

- Added dedicated merchant dashboard with analytics and transactions
- Implemented API Key based authentication for merchants
- Introduced 8-character Short IDs for merchants to use in URLs
- Refactored checkout and payment intent APIs to support multi-gateway
- Enhanced Landing Page with Merchant Portal access and marketing copy
- Fixed Next.js 15 async params build issues
- Updated internal branding to P2CGateway
- Added AyrisTech credits to footer

app/login/page.tsx

@@ -55,7 +55,7 @@ export default function LoginPage() {
                                 required
                                 value={email}
                                 onChange={(e) => setEmail(e.target.value)}
-                                placeholder="admin@froyd.io"
+                                placeholder="admin@p2cgateway.com"
                                 className="w-full pl-14 pr-6 py-4 bg-gray-50 border-none rounded-2xl text-sm font-medium focus:ring-2 focus:ring-blue-500 outline-none"
                             />
                         </div>