Centralize seat capacity accounting and the payment provider registry.

Replace manualProviders.ts with a paymentProviders.ts registry
(automatic vs manual settlement) and move all seat counting into
capacity.ts as the single source of truth: only paid/checked-in tickets
and pending_approval payments hold a seat, so abandoned checkouts never
block sales. Admins can now knowingly approve a payment over capacity
(allowOverCapacity), with the booking and admin UIs updated to match.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/src/routes/payments.ts

@@ -19,6 +19,9 @@ const updatePaymentSchema = z.object({
 const approvePaymentSchema = z.object({
   adminNote: z.string().optional(),
   sendEmail: z.boolean().optional().default(true),
+  // Admin override: confirm the booking even when it puts the event over
+  // capacity. The UI asks for explicit confirmation before sending this.
+  allowOverCapacity: z.boolean().optional().default(false),
 });
 
 const rejectPaymentSchema = z.object({
@@ -317,29 +320,28 @@ paymentsRouter.put('/:id', requireAuth(['admin', 'organizer']), zValidator('json
 // Approve payment (admin) - specifically for pending_approval payments
 paymentsRouter.post('/:id/approve', requireAuth(['admin', 'organizer']), zValidator('json', approvePaymentSchema), async (c) => {
   const id = c.req.param('id');
-  const { adminNote, sendEmail } = c.req.valid('json');
+  const { adminNote, sendEmail, allowOverCapacity } = c.req.valid('json');
   const user = (c as any).get('user');
-  
+
   const payment = await dbGet<any>(
     (db as any)
       .select()
       .from(payments)
       .where(eq((payments as any).id, id))
   );
-  
+
   if (!payment) {
     return c.json({ error: 'Payment not found' }, 404);
   }
-  
+
   // Can approve pending, pending_approval, on_hold, or failed payments.
   // 'failed' covers an admin confirming a payment that was auto-failed or rejected
   // in error; its tickets are cancelled, so recovery re-checks capacity below.
+  // Bare 'pending' covers customers who paid but never clicked "I've paid".
   if (!['pending', 'pending_approval', 'on_hold', 'failed'].includes(payment.status)) {
     return c.json({ error: 'Payment cannot be approved in its current state' }, 400);
   }
 
-  const now = getNow();
-
   // Get the ticket associated with this payment
   const ticket = await dbGet<any>(
     (db as any)
@@ -381,55 +383,35 @@ paymentsRouter.post('/:id/approve', requireAuth(['admin', 'organizer']), zValida
     }
   }
 
-  if (payment.status === 'on_hold' || payment.status === 'failed') {
-    // The seat was released when this booking went on hold or failed - re-check
-    // capacity before confirming it directly.
-    try {
-      await reserveOnHoldBooking(
-        ticket.eventId,
-        ticketsToConfirm.map((t: any) => t.id),
-        'confirmed',
-        'paid',
-        {
-          paidByAdminId: user.id,
-          fromTicketStatuses:
-            payment.status === 'failed' ? ['cancelled', 'on_hold', 'pending'] : ['on_hold'],
-        }
-      );
-    } catch (err) {
-      if (err instanceof HoldCapacityError) {
-        return c.json({
-          error: 'This event is now full. Your spot was released after the payment deadline passed.',
-        }, 400);
+  // Confirm the booking through the shared capacity-checked reservation.
+  // Tickets that already hold a seat ('pending_approval' claims) cost no new
+  // capacity; unseated ones (bare 'pending', on_hold, failed/cancelled) do.
+  // When the event is full, the admin gets a structured over-capacity error and
+  // may retry with allowOverCapacity to knowingly overbook.
+  try {
+    await reserveOnHoldBooking(
+      ticket.eventId,
+      ticketsToConfirm.map((t: any) => t.id),
+      'confirmed',
+      'paid',
+      {
+        paidByAdminId: user.id,
+        fromTicketStatuses:
+          payment.status === 'failed' ? ['cancelled', 'on_hold', 'pending'] : ['on_hold', 'pending'],
+        skipCapacityCheck: allowOverCapacity,
+        ...(adminNote ? { extraPaymentFields: { adminNote } } : {}),
       }
-      throw err;
-    }
-    if (adminNote) {
-      await (db as any)
-        .update(payments)
-        .set({ adminNote })
-        .where(inArray((payments as any).ticketId, ticketsToConfirm.map((t: any) => t.id)));
-    }
-  } else {
-    // Update all payments in the booking to paid
-    for (const t of ticketsToConfirm) {
-      await (db as any)
-        .update(payments)
-        .set({
-          status: 'paid',
-          paidAt: now,
-          paidByAdminId: user.id,
-          adminNote: adminNote || payment.adminNote,
-          updatedAt: now,
-        })
-        .where(eq((payments as any).ticketId, (t as any).id));
-
-      // Update ticket status to confirmed
-      await (db as any)
-        .update(tickets)
-        .set({ status: 'confirmed' })
-        .where(eq((tickets as any).id, (t as any).id));
+    );
+  } catch (err) {
+    if (err instanceof HoldCapacityError) {
+      return c.json({
+        error: 'Approving this payment puts the event over capacity.',
+        code: 'EVENT_OVER_CAPACITY',
+        availableSeats: err.available,
+        requestedSeats: ticketsToConfirm.length,
+      }, 409);
     }
+    throw err;
   }
 
   // Send confirmation emails asynchronously (if sendEmail is true, which is the default)