Delete multiple transactions in a single request. Provide exactly one of:

• all: true — delete every transaction for the organization
• afterDate — delete all transactions created on or after the given ISO 8601 date
• ids — delete specific transactions by UUID (max 1000)

Temporary private data is purged after deletion. If cleanup is incomplete, returns 503; retry the same request to continue cleanup, even if the transaction records have already been deleted.