Enhance payment processing and rental features

- Updated the BTCPay service to support internal Lightning invoices with private route hints, improving payment routing for users with private channels.
- Added reconciliation methods for pending rents and subscriptions to ensure missed payments are processed on startup.
- Enhanced the rental and subscription services to handle payments in satoshis, aligning with Lightning Network standards.
- Improved the rental modal and content detail components to display rental status and pricing more clearly, including a countdown for rental expiration.
- Refactored various components to streamline user experience and ensure accurate rental access checks.

backend/.env.example

@@ -29,6 +29,11 @@ BTCPAY_URL=https://btcpay.yourdomain.com
 BTCPAY_STORE_ID=
 BTCPAY_API_KEY=
 BTCPAY_WEBHOOK_SECRET=
+# Create a separate internal Lightning invoice with privateRouteHints.
+# Only needed when BTCPay's built-in route hints are NOT enabled.
+# If you enabled "Include hop hints" in BTCPay's Lightning settings,
+# leave this as false — BTCPay handles route hints natively.
+BTCPAY_ROUTE_HINTS=false
 
 # User Pool - AWS Cognito
 COGNITO_USER_POOL_ID=