Merge R2-03 Virtual-Tag failure quality (arch-review round 2) [PR #430]

Findings 02/S13 (VT failure/timeout degrades node to Bad quality, no stale-Good
forever), 02/S12 (evaluator retry-once on disposed-race), 02/P7 (compile-cache
clear gated on changed expression set). T11/T12 deferred. STATUS.md conflict
resolved additively. Build clean.

archreview/plans/STATUS.md

@@ -172,3 +172,4 @@ what the unit leg cannot; (c) migrate the 3 xunit v2 holdouts once Akka ships an
 | **R2-06** | 06/S-11 (rank 7), 06/U-7 (rank 8), 06/C-7 | `r2/06-serverhistorian-failfast` (off `1676c8f4`) | `3a049a13`…`4640ecb1` (10 task commits) | **Code-complete, offline-verified.** S-11: fail-fast `ServerHistorianOptionsValidator` (consumer-gated on `ServerHistorian:Enabled` OR `AlarmHistorian:Enabled`, fails empty/non-http(s) Endpoint at startup) + `AddValidatedOptions` wiring + adapter defense-in-depth (`TryCreate`→named `InvalidOperationException`, no more raw `UriFormatException` crash-loop) + `Validate()` warning parity + alarm-only-mode startup warning. U-7: pinned Boolean→Int1 explicit-presence (`HasDataType`) + `HISTGW_BOOL_SANDBOX_TAG` live Boolean EnsureTags leg + retype probe (skip-clean offline) + upsert/retype migration note (`docs/Historian.md`). C-7: keep-populating decision + dead-`Quality` doc comments (0.2.0 C-002). **Live leg operator-gated (T12) — pending a VPN run on a 0.2.0 gateway** (records the observed in-place retype policy back into `docs/Historian.md`; also discharges 06/U-2's full documented run). |
 | **R2-05** | 04/C-1 (High) | `r2/05-adminui-authz` (off `1676c8f4`) | `183b72b7`…`6c1f05cb` (5 commits) | **Code-complete, offline-verified.** All 38 routable AdminUI pages carry an explicit named-policy `@attribute` via new `AdminUiPolicies` constants (`Security/Auth/`). New `ConfigEditor` (Administrator+Designer) gates the 20-page config-authoring surface incl. the 8 driver pages that author live `ResilienceConfig` + `/api/script-analysis/*`; new `AuthenticatedRead` on the 16 read pages; `FleetAdmin`/`DriverOperator` unchanged (literals→constants). Anti-drift guard `PageAuthorizationGuardTests` (bans bare `[Authorize]`/`Roles=`/unknown-policy/unclassified) + `AdminUiPoliciesTests` semantics matrix. Corrections folded in: Reservations + ClusterRedundancy read-only (→`AuthenticatedRead`); Home had no attribute (now `AuthenticatedRead`). AdminUI.Tests 517/517, Security.Tests 80/80. **Live `/run` positive pass deferred (T15)** — docker-dev `DisableLogin=true` auto-admin can't observe deny; negative proof is CI-side (both guard tests). |
 | **R2-01** | 05/STAB-14 (High regression, rank 1), 05/STAB-15 (rank 3), 05/STAB-8 seam | `r2/01-s7-fault-hardening` (off `1676c8f4`) | `fcdcf0e2`…`bdb7ed41` (13 task commits) | **Code-complete, offline-verified.** All prod changes in `S7Driver.cs`. STAB-14: connect-timeout surfaces as `TimeoutException` (not an escaping OCE) at the `EnsureConnectedAsync`/`InitializeAsync` source + `when(token.IsCancellationRequested)` filters on the read/write ensure-wrappers and all three poll-loop OCE catches — subscription poll loops survive an unreachable-host outage and recover (T2 regression RED→GREEN). STAB-15: `IsS7ConnectionFatal` broadened to the ISO-on-TCP framing surface (TPKT/TPDU/WrongNumberOfBytes/`PlcException{WrongNumberReceivedBytes}`, NOT `InvalidDataException`); mid-PDU cancel marks handle dead; probe classifies+marks-dead under the gate. STAB-8 (S7 part): `EnsureConnectedAsync` documented as the R2-09 connect-throttle seam (note-only). Driver.S7.Tests 246/246. **Live outage gate deferred (T11)** — `S7_1500ConnectTimeoutOutageTests` (env `S7_TIMEOUT_OUTAGE_START_CMD`/`STOP_CMD`, SYN-blackhole) skips clean offline; the connect-*timeout* class the `docker restart` bounce can't produce. (Pre-existing unrelated CLI docs-scan test fails at base — out of scope.) |
+| **R2-03** | 02/S13 (rank 5), 02/S12, 02/P7 | `r2/03-vt-failure-quality` (off `1676c8f4`) | `b9775485`…`6bb91e8d` (12 task commits) | **Code-complete, offline-verified.** S13: VT script failure/timeout degrades the node to `OpcUaQuality.Bad` (carrying last-known value) instead of freezing on last-Good forever — additive `EvaluationResult.Quality`, bridge historizes `0x80020000u` BadInternalError, published once per Good→Bad transition gated on all deps arrived (inputs-ready, no cold-start flash), recovery force-publishes next Good. S12: apply-boundary `ClearCompiledScripts` racing an in-flight eval into ObjectDisposedException retried once in `RoslynVirtualTagEvaluator` (re-fetch→recompile into current generation); stress guard reproduces pre-fix, deterministically green post-fix. P7: apply-boundary clear gated on a changed deployed expression set (`HashSet.SetEquals`, ordinal) — identical redeploy / rename-with-same-expressions no longer forces full VT recompile. Runtime.Tests 372/372, RoslynVirtualTagEvaluatorTests 20/20. **Deferred (T11/T12):** full cross-suite sweep + docker-dev live-`/run` (fail→Bad→recover + P7 no-recompile spot-check). |