Phase 2 official close-out. Closes task #209. The 2026-04-18 exit-gate-phase-2-final.md captured Phase 2 state at PR 2 merge — four High/Medium adversarial findings still OPEN, Historian port + alarm subsystem + v1 archive deletion all deferred. Since then: PR 4 closed all four findings end-to-end (High 1 Read subscription-leak, High 2 no reconnect loop, Medium 3 SubscribeAsync doesn't push frames, Medium 4 WriteValuesAsync doesn't await OnWriteComplete — mapped + resolved inline in the new doc), PR 12 landed the richer historian quality mapper, PR 13 shipped GalaxyRuntimeProbeManager with per-Platform/AppEngine ScanState subscriptions + StateChanged events forwarded through the existing OnHostStatusChanged IPC frame, PR 14 wired the alarm subsystem (GalaxyAlarmTracker advising the four alarm-state attributes per IsAlarm=true attribute, raising AlarmTransition events forwarded through OnAlarmEvent IPC frames), Phase 3 PR 18 deleted the v1 source trees, and PR 61 closed V1_ARCHIVE_STATUS.md. Phase 2 is functionally done; this commit is the bookkeeping pass. New exit-gate-phase-2-closed.md at docs/v2/implementation/ — five-stream status table (A/B/C/D/E all complete with the specific close commits named), full resolution table for every 2026-04-18 adversarial finding mapped to the PR 4 resolution, cross-cutting deferrals table marking every one resolved (Historian SDK plugin port → done, subscription push frames → done under Medium 3, Historian-backed HistoryRead → done, alarm subsystem wire-up → done, reconnect-without-recycle → done under High 2, v1 archive deletion → done). Fresh 2026-04-20 test baseline captured from the current v2 tip: 1844 passing + 29 infra-gated skips across 21 test projects, including the net48 x86 Galaxy.Host.Tests suite (107 pass) that exercises the MXAccess COM path on the dev box. Flake observed — Configuration.Tests 70/71 on first full-solution run, 71/71 on retry; logged as a known non-stable flake rather than chased because it did not reproduce. The prior exit-gate-phase-2-final.md is kept in place (historical record of the 2026-04-18 snapshot) but gets a superseded-by banner at the top pointing at the new close-out doc so future readers land on current status first. docs/v2/plan.md Phase 2 section header gains the ✅ CLOSED 2026-04-20 marker + a link to the close-out doc so the top-level plan index reflects reality. "What Phase 2 closed means for Phase 3 and later" section in the new doc captures the downstream contract: Galaxy now runs as a first-class v2 driver with the same capability-interface shape as Modbus / S7 / AbCip / AbLegacy / TwinCAT / FOCAS / OpcUaClient; no v1 code path remains; the 2026-04-13 stability findings persist as named regression tests under tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.E2E/StabilityFindingsRegressionTests.cs so any future refactor reintroducing them trips the test. "Outstanding — not Phase 2 blockers" section lists the four pending non-Phase-2 tasks (#177, #194, #195, #199) so nobody mistakes them for Phase 2 tail work.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/v2/implementation/exit-gate-phase-2-final.md

@@ -1,5 +1,11 @@
 # Phase 2 Final Exit Gate (2026-04-18)
 
+> **⚠️ Superseded by [`exit-gate-phase-2-closed.md`](exit-gate-phase-2-closed.md) (2026-04-20).**
+> This doc captures the snapshot at PR 2 merge — when the four `High` + `Medium` findings
+> in the adversarial review were still OPEN and Historian port + alarm subsystem were still
+> deferred. All of those closed subsequently (PR 4 + PR 12 + PR 13 + PR 14 + PR 61). Kept
+> as historical evidence; consult the close-out doc for current Phase 2 status.
+
 > Supersedes `phase-2-partial-exit-evidence.md` and `exit-gate-phase-2.md`. Captures the
 > as-built state at the close of Phase 2 work delivered across two PRs.