fix: every ticket row gets a fresh short-hash id (no payment_hash reuse)

Previous commit reused the LNbits invoice payment_hash as the
first row's id, so a 3-ticket purchase ended up with one 64-hex
id and two short-hash ids — inconsistent and noisy in My Tickets.

Switch every row to urlsafe_short_hash. The shared payment_hash
column is the join key for invoice lookups (poll endpoint, ws
notifier, on_invoice_paid); rows never need to BE the payment
hash, they only need to point at it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

views_api.py

@@ -612,15 +612,15 @@ async def api_ticket_create(
             extra=extra,
         ),
     )
-    # Multi-ticket purchases land as N rows sharing the LNbits invoice
-    # payment_hash but with distinct `id`s — one independently
-    # scannable QR per attendee. The first row reuses payment_hash as
-    # its id so the legacy single-purchase invariant
-    # (`id == payment_hash`) still holds for quantity == 1 callers.
+    # Each row gets a fresh urlsafe_short_hash id so single- and
+    # multi-ticket purchases stay shape-consistent — every scannable
+    # ticket id is a short hash, never the long bolt11 payment_hash.
+    # The shared `payment_hash` column is the join key for invoice
+    # lookup (poll endpoint, ws notifier, set_ticket_paid loop).
     ticket_ids: list[str] = []
     sats_per_ticket = payment.sat // quantity if quantity else payment.sat
-    for index in range(quantity):
-        row_id = payment.payment_hash if index == 0 else urlsafe_short_hash()
+    for _ in range(quantity):
+        row_id = urlsafe_short_hash()
         await create_ticket(
             payment_hash=payment.payment_hash,
             wallet=event.wallet,