Each export record now keeps a complete BOM snapshot instead of moving
BomItems between records. CutTemplate gains a Revision field that
auto-increments when the content hash changes across exports for the
same drawing+item, and stays the same when the geometry is unchanged.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add find-existing endpoint and upsert logic to POST so re-exporting
a part updates the existing BomItem rather than creating duplicates.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
