# Remaining Deferred Work

Source: `docs/plans/2026-07-08-deferred-work-register.md` (snapshot 2026-07-10).
Everything in the register's "Fix-now" table is already landed via the archreview
plans; what's left are the intentional deferrals below.

## Product / roadmap-locked (revisit needs a decision or a trigger event)

| # | Item | Why deferred | Revisit trigger |
|---|------|--------------|-----------------|
| 8 | Hash-chain tamper evidence (CLI `verify-chain` is a no-op stub) | v1.x by locked decision — append-only DB roles are the current control | A compliance requirement for cryptographic tamper evidence |
| 9 | Parquet audit archival (endpoint returns `501`) | v1.x — the `501` + CLI messaging are honest, not broken | AuditLog partition volume nears the retention ceiling |
| 11 | Central-persisted OPC UA cert-trust audit | Broadcast-to-both-nodes already covers HA | A governance/audit requirement for trust decisions |
| 19 | Bundle signing / cluster-to-cluster pull / differential bundles | v1 manifest hash + AES-GCM held sufficient | A non-repudiation requirement across orgs |
| 17 | Unified notifications + site-calls outbox page | Explicit M9 decision to keep two pages | Operator confusion reports |
| 18 | Folder drag-drop | Permanently closed — menu reorder shipped instead | — (closed) |

## Scale / YAGNI (deferred until load justifies it)

| # | Item | Why deferred | Revisit trigger | Status |
|---|------|--------------|-----------------|--------|
| 10 | Aggregated live alarm stream for Alarm Summary | Snapshot fan-out is acceptable at current instance counts | Latency complaints or >~50 instances/site | ✅ **SHIPPED + MERGED to main 2026-07-10** (`8c888f13`, plan `docs/plans/2026-07-10-aggregated-live-alarm-stream-plan.md`, T1–T8). Transient per-site in-memory live cache (`ISiteAlarmLiveCache`/`SiteAlarmAggregatorActor`) seeded by snapshot fan-out + additive `SubscribeSite` alarm-only gRPC stream; live-cache-driven Alarm Summary with 15s poll fallback; `[PERM]` no-central-store honored (code-reviewer-confirmed); validated options + telemetry; end-to-end trace. Register row moved to Resolved. |
| 22 | KPI history hourly rollups | 90-day retention already bounds the table | `KpiSample` query latency on dashboards | ✅ **SHIPPED + MERGED to main 2026-07-10** (`8c888f13`, plan `docs/plans/2026-07-10-kpi-history-hourly-rollups-plan.md`, T1–T8). Separate `KpiRollupHourly` table (migration `20260710153953`), recorder hourly fold w/ failover-safe lookback re-fold + idempotent upsert, per-metric gauge-vs-rate aggregation, range-threshold query routing (`RollupThresholdHours` 168h), longer rollup retention (365 ≥ 90) + dual purge, one-shot backfill, and 30 d/90 d window buttons. Register row moved to Resolved. |

## Low-priority polish (near-complete, small remainder)

| # | Item | Why deferred | Revisit trigger |
|---|------|--------------|-----------------|
| 12 | Native-alarm-source-override CSV import — Central UI upload button only | CLI + Management API + parser shipped 2026-07-10; the Blazor upload affordance is the only piece left, and it's pure polish (needs a live Blazor smoke) | First request to bulk-import native sources from the UI instead of the CLI |

## New deferrals from review 08 (engineering debt, no defect)

| Item | Why deferred | Revisit trigger |
|------|--------------|-----------------|
| Communication → HealthMonitoring layering inversion | Moving the interface + `SiteHealthState` to Commons ripples across 5 projects for a cosmetic inversion | Next breaking change to `ICentralHealthAggregator` |
| Reference docs for ScriptAnalysis, KpiHistory, DelmiaNotifier | Full StyleGuide-conformant docs are substantial; README claim was scoped instead (PLAN-08 T10) | Next doc-writing session touching those components |
| Test-coverage backfill: SiteCallAudit.Tests, DeploymentManager.Tests | No defect identified; coverage partly lives in ManagementService/Host/Integration suites | First regression escaping either component |
| Failover-timing + broader perf envelope (S&F drain rate, per-subscriber backpressure) | Needs the PLAN-01 two-node rig; placeholder harness already shipped (PLAN-08 T8) | PLAN-01 rig landing |

---

Summary: 12 open deferrals (13th, folder drag-drop #18, is permanently closed).
None are currently actionable without a triggering event or product decision —
except row #12's UI upload button, whose CLI/API/parser core already shipped.