Remove dead Stripe integration

Stripe was wired up but never used:
- No STRIPE_SECRET_KEY in .env
- Card payment step had a 'simulated fallback' that pretended to charge
- Stripe fees (1.4% + 20p) contradict '100% goes to charity' brand promise
- Bank transfer is the primary rail, GoCardless (DD) is the secondary

Removed:
- src/lib/stripe.ts (Stripe client, checkout sessions, webhooks)
- src/app/api/stripe/checkout/route.ts
- src/app/api/stripe/webhook/route.ts
- src/app/p/[token]/steps/card-payment-step.tsx (263 lines)
- 'stripe' and '@stripe/stripe-js' npm packages
- Card option from PaymentStep (payment-step.tsx)
- Card references from confirmation-step.tsx, success/page.tsx
- Stripe from landing page integrations grid
- Stripe from privacy policy sub-processors
- Stripe from terms of service payment references

Type Rail changed: 'bank' | 'gocardless' | 'card' → 'bank' | 'gocardless'
Pledge flow bundle: 19.5kB → 18.2kB (-1.3kB)

Payment options donors now see:
1. Bank Transfer (recommended, zero fees)
2. Direct Debit via GoCardless (1% + 20p, hassle-free)

pledge-now-pay-later/src/app/p/[token]/page.tsx

@@ -9,10 +9,9 @@ import { IdentityStep } from "./steps/identity-step"
 import { ConfirmationStep } from "./steps/confirmation-step"
 import { BankInstructionsStep } from "./steps/bank-instructions-step"
 import { ExternalRedirectStep } from "./steps/external-redirect-step"
-import { CardPaymentStep } from "./steps/card-payment-step"
 import { DirectDebitStep } from "./steps/direct-debit-step"
 
-export type Rail = "bank" | "gocardless" | "card"
+export type Rail = "bank" | "gocardless"
 
 export interface PledgeData {
   amountPence: number
@@ -143,7 +142,7 @@ export default function PledgePage() {
   // Step 2: Payment method selected (only for "now" self-payment mode)
   const handleRailSelected = (rail: Rail) => {
     setPledgeData((d) => ({ ...d, rail }))
-    setStep(rail === "bank" ? 3 : rail === "card" ? 6 : 8)
+    setStep(rail === "bank" ? 3 : 8)
   }
 
   // Submit pledge (from identity step, or card/DD steps)
@@ -243,20 +242,19 @@ export default function PledgePage() {
         installmentAmount={pledgeData.installmentCount ? Math.ceil(pledgeData.amountPence / pledgeData.installmentCount) : undefined}
       />
     ),
-    6: <CardPaymentStep amount={pledgeData.amountPence} eventName={eventInfo?.name || ""} eventId={eventInfo?.id || ""} qrSourceId={eventInfo?.qrSourceId || null} onComplete={submitPledge} />,
     7: pledgeResult && <ExternalRedirectStep pledge={pledgeResult} amount={pledgeData.amountPence} eventName={eventInfo?.name || ""} externalUrl={eventInfo?.externalUrl || ""} externalPlatform={eventInfo?.externalPlatform} donorPhone={pledgeData.donorPhone} />,
     8: <DirectDebitStep amount={pledgeData.amountPence} eventName={eventInfo?.name || ""} organizationName={eventInfo?.organizationName || ""} eventId={eventInfo?.id || ""} qrSourceId={eventInfo?.qrSourceId || null} onComplete={submitPledge} />,
   }
 
   const backableSteps = new Set([1, 2, 3, 6, 8])
   const getBackStep = (s: number): number => {
-    if (s === 6 || s === 8) return 2  // card/DD → payment method
+    if (s === 8) return 2  // DD → payment method
     if (s === 3 && pledgeData.scheduleMode !== "now") return 1 // deferred identity → schedule
     if (s === 3) return 2 // bank identity → payment method
     return s - 1
   }
 
-  const progressMap: Record<number, number> = { 0: 8, 1: 25, 2: 40, 3: 60, 4: 100, 5: 100, 6: 60, 7: 100, 8: 60 }
+  const progressMap: Record<number, number> = { 0: 8, 1: 25, 2: 40, 3: 60, 4: 100, 5: 100, 7: 100, 8: 60 }
   const progressPercent = progressMap[step] || 10
 
   return (