Skip corrupt KeyframeData rows during full system backup

A single row with malformed KeyframeTicks JSON (e.g. a truncated array
from an interrupted write) currently aborts the entire backup, because
the try/catch in BackupService.CreateBackupAsync only wraps
serialization of an already-materialized entity, not the enumeration
itself. EF Core throws JsonReaderException from MoveNextAsync() while
materializing the corrupt row, which propagates past that catch block.

Switch to manual enumerator iteration so MoveNextAsync() failures can
be caught per-row, logged as a warning identifying the affected table,
and skipped, allowing the remaining rows and the rest of the backup to
complete.

Fixes #17216

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

0 files changed, 0 insertions, 0 deletions