Increase the Prisma interactive transaction timeout from the default 5s
to 30s so that the four sequential nullification + delete queries complete
reliably on a seeded database (P2028 timeout was the root cause).
Wrap the transaction in a try/catch so that if a timeout does still occur
the user sees "Delete timed out — please try again." instead of an
unhandled 500 that previously manifested as the misleading "referenced in
submitted or active purchase orders" error message.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
