Architect transaction boundaries and partial success DML

• Database.insert(records, false) for partial success collecting Database.Error per row • Log failed rows with error messages to staging object for user remediation • AllOrNone=false implications on trigger side effects for partial batches • Savepoints for explicit rollback of sub-operations within single transaction • Separate validation pass in before trigger vs relying on DML error collection • UI surfacing partial success counts and downloadable error CSV • Retry job for corrected failed rows without reprocessing successes