Builds on @mrsucesso's durable-marker recovery (previous commit):
- GET /api/hermes/update/receipt — the full durable receipt (steps,
skips, gateway restart outcome, fleet matrix) + compact summary; the
authoritative update-outcome record (written by every run since
#91283, including refused/failed).
- /api/actions/hermes-update/status now attaches the receipt summary,
and when BOTH the in-memory registries and the update.log marker are
gone (dashboard restarted + log rotated — the #81193 state), a
finished receipt reports the outcome: success→0, partial→1. A
still-running receipt proves nothing (clients keep polling).
- Desktop (updates.ts): the apply poll reads the attached receipt — a
finished receipt whose run started at/after this apply is
authoritative, replacing timeout-based failure inference across the
update's restart gap ('Backend update failed' on successful updates,
#81193; 'boot failed' during update restarts, #87359).
Live-verified: real uvicorn server + real UpdateReceipt writer (the
exact code hermes update runs) over real HTTP — receipt endpoint 200
with summary; #81193 state (no registries, no marker) reports success
from the receipt alone; partial receipt with a DOWN fleet row maps to
exit 1 (no false success).