## Summary
Replace the renderer-only workspace-ID cache with bounded validated
display snapshots in backend-owned state.ui.serviceUsage. Cache survives
recreated renderer/backend/workspace identity, keyed by authenticated
service/discovery/execution-host/folder fingerprint and period/timezone.
Eight entries, 1 MiB maximum; no plaintext credentials or paths.
Preferences does not write the opener's client-state journal.
Show previous totals/charts immediately with a cached-state label while
revalidating; preserve them on error. Hidden/unmounted Stats starts no
reads, cancels trailing work and fences late results. Visibility resumes
one read; execution hints use the existing activity cooldown instead of
one native scan per descendant. Manual refresh, period, reconnect and
deletion/pruning paths retained.
## Validation
- Rebased on current dev 7a2ee897e, retaining #1037 shared fixture
cache/shutdown and token UI plus #1039 launcher changes.
- Server/UI typechecks pass; cache/scheduler units 8/8; browser
service-usage 5/5, usage-metrics 4/4, status-tokens 4/4, sequentially.
- Real renderer AND backend recreation with a two-second stats delay:
2098 ms cold / 68 ms restored, then fresh totals replace cached values.
- Hidden-start regression: base makes one unwanted read; fixed makes
zero. Tests cover hidden events, visibility, burst scheduling, identity
changes, retention/errors and malformed cache bounds.
- Isolated native fixture with four synthetic sessions passes; repeated
native reads ~15–19 ms. OpenCode still repeats aggregation; no claim to
optimize large-history scans.
- No app/shared daemon/user data touched. Live installed app and
non-Windows native acceptance not tested.
## Oversized touched files
http-server.ts ~2446 lines; api-client.ts ~817; 10 locale settings.ts
files ~735–749. No unrelated refactor.
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