Enable business payments and bank transfers in Stripe checkout

Payment Methods Added:
- ACH bank transfers (us_bank_account) for US customers
- Stripe Link for saved payment methods including bank accounts
- Kept credit/debit card payments

Business Payment Features:
- customer_creation: 'always' - Creates Stripe customer for each payment
- billing_address_collection: 'required' - Collects full billing address
- phone_number_collection: Enabled for contact information
- tax_id_collection: Enabled for business tax ID (VAT, EIN, etc.)

Benefits:
- Businesses can now enter their tax ID for invoicing
- Customers can pay via bank transfer (ACH) as well as cards
- Full billing information collected for business records
- Stripe Link provides one-click checkout for returning customers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

server/routes/checkout.js

@@ -92,12 +92,20 @@ router.post('/create-session', async (req, res) => {
 
     // Create Stripe Checkout Session
     const session = await stripe.checkout.sessions.create({
-      payment_method_types: ['card'],
+      payment_method_types: ['card', 'us_bank_account', 'link'],
       line_items: lineItems,
       mode: 'payment',
       success_url: `${process.env.FRONTEND_URL}/checkout/success?session_id={CHECKOUT_SESSION_ID}`,
       cancel_url: `${process.env.FRONTEND_URL}/checkout/cancel`,
       customer_email: customerEmail,
+      customer_creation: 'always', // Always create a customer for payment tracking
+      billing_address_collection: 'required', // Collect billing address for business payments
+      phone_number_collection: {
+        enabled: true, // Collect phone number
+      },
+      tax_id_collection: {
+        enabled: true, // Allow customers to enter business tax ID
+      },
       metadata: {
         tons: tons.toString(),
         portfolioId: portfolioId.toString(),