simplify: zakat yes/no per campaign, remove 5 fund types, add I've Donated button for external pledges

- Event.zakatEligible (boolean) replaces Organization.zakatEnabled + 5 fund types
- Pledge.isZakat (boolean) replaces Pledge.fundType enum
- Removed fundAllocation from Event (campaign IS the allocation)
- Identity step: simple checkbox instead of 5-option grid
- Campaign creation: Zakat toggle + optional external URL for self-payment
- External redirect step: 'I've Donated' button calls /api/pledges/[id]/mark-initiated
- Landing page: simplified Zakat section (toggle preview, not 5 fund descriptions)
- Settings: removed org-level Zakat toggle (it's per campaign now)
- Migration: ALTER TABLE adds zakatEligible/isZakat, drops fundAllocation

pledge-now-pay-later/src/app/api/pledges/route.ts

@@ -105,7 +105,7 @@ export async function POST(request: NextRequest) {
       )
     }
 
-    const { amountPence, rail, donorName, donorEmail, donorPhone, giftAid, fundType, eventId, qrSourceId, scheduleMode, dueDate, installmentCount, installmentDates } = parsed.data
+    const { amountPence, rail, donorName, donorEmail, donorPhone, giftAid, isZakat, eventId, qrSourceId, scheduleMode, dueDate, installmentCount, installmentDates } = parsed.data
 
     // Get event + org
     const event = await prisma.event.findUnique({
@@ -161,7 +161,7 @@ export async function POST(request: NextRequest) {
               donorEmail: donorEmail || null,
               donorPhone: donorPhone || null,
               giftAid,
-              fundType: fundType || null,
+              isZakat: isZakat || false,
               eventId,
               qrSourceId: qrSourceId || null,
               organizationId: org.id,
@@ -231,7 +231,7 @@ export async function POST(request: NextRequest) {
           donorEmail: donorEmail || null,
           donorPhone: donorPhone || null,
           giftAid,
-          fundType: fundType || null,
+          isZakat: isZakat || false,
           eventId,
           qrSourceId: qrSourceId || null,
           organizationId: org.id,