ONE additional restic call tagged [felhom-offbox, _shares] carrying the payload
staging dir + every mandatory share folder. Hooked into runOffboxInternal AFTER the
per-app loop and BEFORE retention, so forget --group-by host,tags covers the _shares
group with no flag change. Reuses resticStep, the caller's repo-ensure and
single-flight, and the SAME enlargement-gate arithmetic.
- quota gate degrades the push to MANIFEST-ONLY, never to nothing
- EnlargedBlocked keeps the RAW _shares key (templates index by it); the display
mapping applies only at the notification + Hungarian-prose boundaries
- OffboxTarget gains SharesLastRun/Status/Count for per-tier page truth
- zero-toggle notice suppressed when the shares leg provided coverage
- reserved-name defense: an app keyed _shares is excluded from the run loudly
RED-PROOFS RUN AND REVERTED (all fired):
1. shares leg appends into the app's argv -> isolation test FAILS
2. mandatory->offsite mapping inverted -> Scenario A + B FAIL
3. manifest-only degradation dropped -> Scenario C FAILS
