task-galaxy-e2e branch — non-FOCAS work-in-progress snapshot

Catch-all commit for pending work on the task-galaxy-e2e branch that
wasn't part of the FOCAS migration. Grouping by topic so future per-topic
commits can be cherry-picked if needed.

TwinCAT
- src/.../Driver.TwinCAT/AdsTwinCATClient.cs + TwinCATDriverFactoryExtensions.cs:
  factory-registration extensions + ADS client refinements.
- src/.../Driver.TwinCAT.Cli/Commands/BrowseCommand.cs: new browse command
  for the TwinCAT test-client CLI.
- tests/.../Driver.TwinCAT.IntegrationTests/TwinCAT3SmokeTests.cs + TwinCatProject/:
  fixture scaffold with a minimal POU + README pointing at the TCBSD/ESXi
  VM for e2e.
- docs/Driver.TwinCAT.Cli.md + docs/drivers/TwinCAT-Test-Fixture.md:
  documentation for the above.
- docs/v3/twincat-backlog.md: forward-looking backlog seed.

Admin UI + fleet status
- src/.../Admin/Components/Pages/Clusters/DriversTab.razor + Hosts.razor:
  UI refresh for fleet-status rendering.
- src/.../Admin/Hubs/FleetStatusHub.cs + FleetStatusPoller.cs +
  Admin/Program.cs: SignalR hub + poller plumbing for live fleet data.
- tests/.../Admin.Tests/FleetStatusPollerTests.cs: poller coverage.

Server + redundancy runtime (Phase 6.3 follow-ups)
- src/.../Server/Hosting/RedundancyPublisherHostedService.cs: HostedService
  that owns the RedundancyStatePublisher lifecycle + wires peer reachability.
- src/.../Server/Redundancy/ServerRedundancyNodeWriter.cs: OPC UA
  variable-node writer binding ServiceLevel + ServerUriArray to the
  publisher's events.
- src/.../Server/Program.cs + Server.csproj: hosted-service registration.
- tests/.../Server.Tests/ServerRedundancyNodeWriterTests.cs +
  Server.Tests.csproj: coverage for the above.

Configuration
- src/.../Configuration/Validation/DraftValidator.cs +
  tests/.../Configuration.Tests/DraftValidatorTests.cs: draft-validation
  refinements.

E2E scripts (shared infrastructure)
- scripts/e2e/README.md + _common.ps1 + test-all.ps1: shared helpers + the
  all-drivers test-all runner.
- scripts/e2e/test-opcuaclient.ps1: OPC UA Client e2e runner.

Docs
- docs/v2/implementation/phase-6-{1,2,3,4}*.md + exit-gate-phase-{3,7}.md:
  phase-gate + implementation doc updates.
- docs/v2/plan.md: top-level plan refresh.
- docs/v2/redundancy-interop-playbook.md: client interop playbook for the
  Phase 6.3 redundancy-runtime work.

Two orphan FOCAS docs remain on disk but deliberately unstaged —
docs/v2/focas-deployment.md and docs/v2/implementation/focas-simulator-plan.md
describe the now-retired Tier-C topology and should either be rewritten
or deleted in a follow-up.

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

docs/v2/plan.md

@@ -689,7 +689,7 @@ Galaxy.Proxy ──→ Galaxy.Shared ←── Galaxy.Host
 
 **Decided:**
 - Mono-repo (Decision #31 above).
-- `Core.Abstractions` is **internal-only for now** — no standalone NuGet. Keep the contract mutable while the first 8 drivers are being built; revisit publishing after Phase 5 when the shape has stabilized. Design the contract *as if* it will eventually be public (no leaky types, stable names) to minimize churn later.
+- `Core.Abstractions` is **internal-only for now** — no standalone NuGet. Keep the contract mutable while the first 8 drivers are being built; revisit publishing after the driver fleet (originally Phase 5, folded into the Phase 3 umbrella — see exit gate) once the shape has stabilized. Design the contract *as if* it will eventually be public (no leaky types, stable names) to minimize churn later.
 
 ---
 
@@ -742,24 +742,30 @@ Each step leaves the system runnable. The generic extraction is effectively free
 10. **Build `Galaxy.Proxy`** — .NET 10 in-process proxy implementing IDriver interfaces, forwarding over IPC
 11. **Validate parity** — v2 Galaxy driver must pass the same integration tests as v1
 
-**Phase 3 — Modbus TCP driver (prove the abstraction)**
-12. **Build `Driver.ModbusTcp`** — NModbus, config-driven tags from central DB, internal poll loop, device-as-folder hierarchy
-13. **Add Modbus config screens to Admin** (first driver-specific config UI)
+**Phase 3 — Driver fleet (all seven non-Galaxy drivers) — ✅ CLOSED 2026-04-23** (see [`implementation/exit-gate-phase-3.md`](implementation/exit-gate-phase-3.md))
 
-**Phase 4 — PLC drivers**
-14. **Build `Driver.AbCip`** — libplctag, ControlLogix/CompactLogix symbolic tags + Admin config screens
-15. **Build `Driver.AbLegacy`** — libplctag, SLC 500/MicroLogix file-based addressing + Admin config screens
-16. **Build `Driver.S7`** — S7netplus, Siemens S7-300/400/1200/1500 + Admin config screens
-17. **Build `Driver.TwinCat`** — Beckhoff.TwinCAT.Ads v6, native ADS notifications, symbol upload + Admin config screens
+Originally split across Phase 3 (Modbus alone), Phase 4 (PLC drivers), and
+Phase 5 (specialty drivers). In execution, once `Core.Abstractions` had
+stabilised under Phase 1 + Phase 2, each driver landed as its own stream
+rather than as a gated mini-phase; the phase numbers were folded into a
+single umbrella. Shipped:
 
-**Phase 5 — Specialty drivers**
-18. **Build `Driver.Focas`** — FANUC FOCAS2 P/Invoke, pre-defined CNC tag set, PMC/macro config + Admin config screens
-19. **Build `Driver.OpcUaClient`** — OPC UA client gateway/aggregation, namespace remapping, subscription proxying + Admin config screens
+12. **`Driver.Modbus`** — NModbus, config-driven tags, internal poll loop, device-as-folder hierarchy (umbrella closure #210)
+13. **`Driver.AbCip`** — libplctag, ControlLogix/CompactLogix symbolic tags (#211, live-booted under #220)
+14. **`Driver.AbLegacy`** — libplctag, SLC 500 / MicroLogix / PLC-5 file-based addressing (#213, live-booted under #222)
+15. **`Driver.S7`** — S7netplus, Siemens S7-300/400/1200/1500 (#212, live-booted under #220)
+16. **`Driver.TwinCAT`** — Beckhoff.TwinCAT.Ads v7, native ADS notifications, symbol upload (factory wired 2026-04-23; wire-live deferred, #221)
+17. **`Driver.FOCAS`** — FANUC FOCAS2 P/Invoke via Tier-C out-of-process `Driver.FOCAS.Host` (#220 five-PR split; wire-live deferred, #222 follow-up)
+18. **`Driver.OpcUaClient`** — OPC UA client gateway / aggregation, namespace remapping, subscription proxying (scaffold #66; live-boot 5/8 stages via `test-opcuaclient.ps1`)
+
+Supporting infrastructure: `DriverFactoryRegistry` + `DriverInstanceBootstrapper`
+(#248); per-driver test-client CLI suite (#249–#251); e2e test scripts with
+aggregate runner (#253); server-side factory + seed SQL per driver (#210–#213).
 
 **Decided:**
 - **Parity test for Galaxy**: existing v1 IntegrationTests suite + scripted Client.CLI walkthrough (see Section 4 above).
 - **Timeline**: no hard deadline. Each phase ships when it's right — tests passing, Galaxy parity bar met. Quality cadence over calendar cadence.
-- **FOCAS SDK**: license already secured. Phase 5 can proceed as scheduled; `Fwlib64.dll` available for P/Invoke.
+- **FOCAS SDK**: license already secured. FOCAS driver shipped as part of the Phase 3 umbrella with Tier-C host; `Fwlib64.dll` available for P/Invoke (wire-level live-boot gated on lab rig, #222 follow-up).
 
 ---