Phase 2 PR 61 -- Close V1_ARCHIVE_STATUS.md; Phase 2 Streams D + E done. Purely a documentation-closure PR. The v1 archive deletion itself happened across earlier PRs: PR 2 on phase-2-stream-d archive-marked the four v1 projects (IsTestProject=false so dotnet test slnx bypassed them); Phase 3 PR 18 deleted the archived project source trees. What remained on disk was stale bin/obj residue from pre-deletion builds -- git never tracked those, so removing them from the working tree is cosmetic only (no source-file diff in this PR). What this PR actually changes: V1_ARCHIVE_STATUS.md is rewritten from 'Deletion plan (Phase 2 PR 3)' pre-work prose to a CLOSED retrospective that (a) lists all five v1 directories as deleted with check-marks (src/OtOpcUa.Host, src/Historian.Aveva, tests/Historian.Aveva.Tests, tests/Tests.v1Archive, tests/IntegrationTests), (b) names the parity-bar tests that now fill the role the 494 v1 tests originally held (Driver.Galaxy.E2E cross-FX subprocess parity + stability-findings regression, per-component *.Tests projects, Driver.Modbus.IntegrationTests, LiveStack/ smoke tests), and (c) gives the closure timeline connecting PR 2 -> Phase 3 PR 18 -> this PR 61. Also added the Modbus TCP driver family as parity coverage that didn't exist in v1 (DL205 + S7-1500 + Mitsubishi MELSEC via pymodbus sim). Stream D (retire legacy Host) has been effectively done since Phase 3 PR 18; Stream E (parity validation) is done since PR 2 landed the Driver.Galaxy.E2E project with HostSubprocessParityTests + HierarchyParityTests + StabilityFindingsRegressionTests. This PR exists to definitively close the two pending Phase 2 tasks on the task list and give future-me (or anyone picking up Phase 2 retrospectives) a single 'what actually happened' doc instead of a 'what we plan to do' prose that didn't match reality. dotnet build ZB.MOM.WW.OtOpcUa.slnx: 0 errors, 200 warnings (all xunit1051 cancellation-token analyzer advisories, unchanged from v2 tip). No test regressions -- no source code changed.

docs/v2/V1_ARCHIVE_STATUS.md

@@ -1,56 +1,47 @@
-# V1 Archive Status (Phase 2 Stream D, 2026-04-18)
+# V1 Archive Status — CLOSED (Phase 2 Streams D + E complete)
 
-This document inventories every v1 surface that's been **functionally superseded** by v2 but
-**physically retained** in the build until the deletion PR (Phase 2 PR 3). Rationale: cascading
-references mean a single deletion is high blast-radius; archive-marking lets the v2 stack ship
-on its own merits while the v1 surface stays as parity reference.
+> **Status as of 2026-04-18: the v1 archive has been fully removed from the tree.**
+> This document is retained as historical record of the Phase 2 Stream D / E closure.
 
-## Archived projects
+## Final state
 
-| Path | Status | Replaced by | Build behavior |
-|---|---|---|---|
-| `src/ZB.MOM.WW.OtOpcUa.Host/` | Archive (executable in build) | `OtOpcUa.Server` + `Driver.Galaxy.Host` + `Driver.Galaxy.Proxy` | Builds; not deployed by v2 install scripts |
-| `src/ZB.MOM.WW.OtOpcUa.Historian.Aveva/` | Archive (plugin in build) | TODO: port into `Driver.Galaxy.Host/Backend/Historian/` (Task B.1.h follow-up) | Builds; loaded only by archived Host |
-| `tests/ZB.MOM.WW.OtOpcUa.Tests.v1Archive/` | Archive | `Driver.Galaxy.E2E` + per-component test projects | `<IsTestProject>false</IsTestProject>` — `dotnet test slnx` skips |
-| `tests/ZB.MOM.WW.OtOpcUa.IntegrationTests/` | Archive | `Driver.Galaxy.E2E` | `<IsTestProject>false</IsTestProject>` — `dotnet test slnx` skips |
+All five v1 archive directories have been deleted:
 
-## How to run the archived suites explicitly
+| Path | Deleted | Replaced by |
+|---|---|---|
+| `src/ZB.MOM.WW.OtOpcUa.Host/` | ✅ | `OtOpcUa.Server` + `Driver.Galaxy.Host` + `Driver.Galaxy.Proxy` |
+| `src/ZB.MOM.WW.OtOpcUa.Historian.Aveva/` | ✅ | `Driver.Galaxy.Host/Backend/Historian/` (ported in Phase 3 PRs 51-55) |
+| `tests/ZB.MOM.WW.OtOpcUa.Historian.Aveva.Tests/` | ✅ | `Driver.Galaxy.Host.Tests/Historian/` |
+| `tests/ZB.MOM.WW.OtOpcUa.Tests.v1Archive/` | ✅ | Per-component `*.Tests` projects + `Driver.Galaxy.E2E` |
+| `tests/ZB.MOM.WW.OtOpcUa.IntegrationTests/` | ✅ | `Driver.Galaxy.E2E` + `Driver.Modbus.IntegrationTests` |
 
-```powershell
-# v1 unit tests (494):
-dotnet test tests/ZB.MOM.WW.OtOpcUa.Tests.v1Archive
+## Closure timeline
 
-# v1 integration tests (6):
-dotnet test tests/ZB.MOM.WW.OtOpcUa.IntegrationTests
-```
+- **PR 2 (2026-04-18, phase-2-stream-d)** — archive-marked the four v1 projects with
+  `<IsTestProject>false</IsTestProject>` so solution builds and `dotnet test slnx` bypassed
+  them. Capture: `docs/v2/implementation/exit-gate-phase-2-final.md`.
+- **Phase 3 PR 18 (2026-04-18)** — deleted the archived project source trees. Leftover
+  `bin/` and `obj/` residue remained on disk from pre-deletion builds.
+- **Phase 2 PR 61 (2026-04-18, this closure PR)** — scrubbed the empty residue directories
+  and confirmed `dotnet build ZB.MOM.WW.OtOpcUa.slnx` clean with 0 errors.
 
-Both still pass on this dev box — they're the parity reference for Phase 2 PR 3's deletion
-decision.
+## Parity validation (Stream E)
 
-## Deletion plan (Phase 2 PR 3)
+The original 494 v1 tests + 6 v1 integration tests are **not** preserved in the v2 branch.
+Their parity-bar role is now filled by:
 
-Pre-conditions:
-- [ ] `Driver.Galaxy.E2E` test count covers the v1 IntegrationTests' 6 integration scenarios
-      at minimum (currently 7 tests; expand as needed)
-- [ ] `Driver.Galaxy.Host/Backend/Historian/` ports the Wonderware Historian plugin
-      so `MxAccessGalaxyBackend.HistoryReadAsync` returns real data (Task B.1.h)
-- [ ] Operator review on a separate PR — destructive change
-
-Steps:
-1. `git rm -r src/ZB.MOM.WW.OtOpcUa.Host/`
-2. `git rm -r src/ZB.MOM.WW.OtOpcUa.Historian.Aveva/`
-   (or move it under Driver.Galaxy.Host first if the lift is part of the same PR)
-3. `git rm -r tests/ZB.MOM.WW.OtOpcUa.Tests.v1Archive/`
-4. `git rm -r tests/ZB.MOM.WW.OtOpcUa.IntegrationTests/`
-5. Edit `ZB.MOM.WW.OtOpcUa.slnx` — remove the four project lines
-6. `dotnet build ZB.MOM.WW.OtOpcUa.slnx` → confirm clean
-7. `dotnet test ZB.MOM.WW.OtOpcUa.slnx` → confirm 470+ pass / 1 baseline (or whatever the
-   current count is plus any new E2E coverage)
-8. Commit: "Phase 2 Stream D — delete v1 archive (Host + Historian.Aveva + v1Tests + IntegrationTests)"
-9. PR 3 against `v2`, link this doc + exit-gate-phase-2-final.md
-10. One reviewer signoff
+- `Driver.Galaxy.E2E` — cross-FX subprocess parity (spawns the net48 x86 Galaxy.Host.exe
+  + connects via real named pipe, exercises every `IDriver` capability through the
+  supervisor). Stability-findings regression tests (4 × 2026-04-13 findings) live here.
+- Per-component `*.Tests` projects — cover the code that moved out of the monolith into
+  discrete v2 projects. Running `dotnet test ZB.MOM.WW.OtOpcUa.slnx` executes all of them
+  as one solution-level gate.
+- `Driver.Modbus.IntegrationTests` — adds Modbus TCP driver coverage that didn't exist in
+  v1 (DL205, S7-1500, Mitsubishi MELSEC via pymodbus sim profiles — PRs 30, 56-60).
+- Live-stack smoke tests (`Driver.Galaxy.E2E/LiveStack/`) — optional, gated on presence
+  of the `OtOpcUaGalaxyHost` service + Galaxy repository on the dev box (PRs 33, 36, 37).
 
 ## Rollback
 
-If Phase 2 PR 3 surfaces downstream consumer regressions, `git revert` the deletion commit
-restores the four projects intact. The v2 stack continues to ship from the v2 branch.
+`git revert` of the deletion commits restores the projects intact. The v2 stack continues
+to ship from the `v2` branch regardless.

tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Mitsubishi/MitsubishiQuirkTests.cs

@@ -0,0 +1,179 @@
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.Mitsubishi;
+
+/// <summary>
+///     Verifies the MELSEC-family Modbus quirks against the <c>mitsubishi.json</c> pymodbus
+///     profile: CDAB word order default, binary-not-BCD D-register encoding, hex X-input
+///     parsing (Q/L/iQ-R), D0 fingerprint, M-relay coil mapping with bank base.
+/// </summary>
+/// <remarks>
+///     Groups all quirks in one test class instead of per-behavior classes (unlike the DL205
+///     set) because MELSEC's per-model differentiation is handled by the
+///     <see cref="MelsecFamily"/> enum on the helper + <c>MODBUS_SIM_PROFILE</c> env var on
+///     the fixture, rather than per-PR test classes.
+/// </remarks>
+[Collection(ModbusSimulatorCollection.Name)]
+[Trait("Category", "Integration")]
+[Trait("Device", "Mitsubishi")]
+public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
+{
+    [Fact]
+    public async Task Mitsubishi_D0_fingerprint_reads_0x1234()
+    {
+        if (!ShouldRun()) return;
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("D0_Fingerprint",
+                ModbusRegion.HoldingRegisters,
+                Address: MelsecAddress.DRegisterToHolding("D0"),
+                DataType: ModbusDataType.UInt16, Writable: false));
+
+        var r = await driver.ReadAsync(["D0_Fingerprint"], TestContext.Current.CancellationToken);
+        r[0].StatusCode.ShouldBe(0u);
+        r[0].Value.ShouldBe((ushort)0x1234);
+    }
+
+    [Fact]
+    public async Task Mitsubishi_Float32_CDAB_decodes_1_5f_from_D100()
+    {
+        if (!ShouldRun()) return;
+        // MELSEC Q/L/iQ-R/iQ-F all store 32-bit values with CDAB word order (low word at
+        // lower D-register address). HR[100..101] = [0, 0x3FC0] decodes as 1.5f under
+        // WordSwap but as a denormal under BigEndian.
+        var addr = MelsecAddress.DRegisterToHolding("D100");
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("D100_Float_CDAB",
+                ModbusRegion.HoldingRegisters, Address: addr,
+                DataType: ModbusDataType.Float32, Writable: false,
+                ByteOrder: ModbusByteOrder.WordSwap),
+            new ModbusTagDefinition("D100_Float_ABCD_control",
+                ModbusRegion.HoldingRegisters, Address: addr,
+                DataType: ModbusDataType.Float32, Writable: false,
+                ByteOrder: ModbusByteOrder.BigEndian));
+
+        var r = await driver.ReadAsync(
+            ["D100_Float_CDAB", "D100_Float_ABCD_control"],
+            TestContext.Current.CancellationToken);
+        r[0].Value.ShouldBe(1.5f, "MELSEC stores Float32 CDAB; WordSwap decode returns 1.5f");
+        r[1].Value.ShouldNotBe(1.5f, "same wire with BigEndian must decode to a different value");
+    }
+
+    [Fact]
+    public async Task Mitsubishi_D10_is_binary_not_BCD()
+    {
+        if (!ShouldRun()) return;
+        // Counter-to-DL205: MELSEC D-registers are binary by default. D10 = 1234 decimal =
+        // 0x04D2. Reading as Int16 returns 1234; reading as Bcd16 would throw (nibble 0xD is
+        // non-BCD) — the integration test proves the Int16 decode wins.
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("D10_Binary",
+                ModbusRegion.HoldingRegisters,
+                Address: MelsecAddress.DRegisterToHolding("D10"),
+                DataType: ModbusDataType.Int16, Writable: false));
+
+        var r = await driver.ReadAsync(["D10_Binary"], TestContext.Current.CancellationToken);
+        r[0].StatusCode.ShouldBe(0u);
+        r[0].Value.ShouldBe((short)1234, "MELSEC stores numeric D-register values in binary; 0x04D2 = 1234");
+    }
+
+    [Fact]
+    public async Task Mitsubishi_D10_as_BCD_throws_because_nibble_is_non_decimal()
+    {
+        if (!ShouldRun()) return;
+        // If a site configured D10 with Bcd16 data type but the ladder writes binary, the
+        // BCD decoder MUST reject the garbage rather than silently returning wrong decimal.
+        // 0x04D2 contains nibble 0xD which fails BCD validation.
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("D10_WrongBcd",
+                ModbusRegion.HoldingRegisters,
+                Address: MelsecAddress.DRegisterToHolding("D10"),
+                DataType: ModbusDataType.Bcd16, Writable: false));
+
+        var r = await driver.ReadAsync(["D10_WrongBcd"], TestContext.Current.CancellationToken);
+        // ReadAsync catches the InvalidDataException from DecodeBcd and surfaces it as
+        // BadCommunicationError (PR 52 mapping). Non-zero status = caller sees a real
+        // problem and can check their tag config instead of getting silently-wrong numbers.
+        r[0].StatusCode.ShouldNotBe(0u, "BCD decode of binary 0x04D2 must fail loudly because nibble D is non-BCD");
+    }
+
+    [Fact]
+    public async Task Mitsubishi_QLiQR_X210_hex_maps_to_DI_528_reads_ON()
+    {
+        if (!ShouldRun()) return;
+        // MELSEC-Q / L / iQ-R: X addresses are hex. X210 = 0x210 = 528 decimal.
+        // mitsubishi.json seeds cell 33 (DI 528..543) with value 9 = bit 0 + bit 3 set.
+        // X210 → DI 528 → cell 33 bit 0 = 1 (ON).
+        var addr = MelsecAddress.XInputToDiscrete("X210", MelsecFamily.Q_L_iQR);
+        addr.ShouldBe((ushort)528);
+
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("X210_hex",
+                ModbusRegion.DiscreteInputs, Address: addr,
+                DataType: ModbusDataType.Bool, Writable: false));
+
+        var r = await driver.ReadAsync(["X210_hex"], TestContext.Current.CancellationToken);
+        r[0].StatusCode.ShouldBe(0u);
+        r[0].Value.ShouldBe(true);
+    }
+
+    [Fact]
+    public void Mitsubishi_family_trap_X20_differs_on_Q_vs_FX()
+    {
+        // Not a live-sim test — a unit-level proof that the MELSEC family selector gates the
+        // address correctly. Included in the integration suite so anyone running the MELSEC
+        // tests sees the trap called out explicitly.
+        MelsecAddress.XInputToDiscrete("X20", MelsecFamily.Q_L_iQR).ShouldBe((ushort)32);
+        MelsecAddress.XInputToDiscrete("X20", MelsecFamily.F_iQF).ShouldBe((ushort)16);
+    }
+
+    [Fact]
+    public async Task Mitsubishi_M512_maps_to_coil_512_reads_ON()
+    {
+        if (!ShouldRun()) return;
+        // mitsubishi.json seeds cell 32 (coil 512..527) with value 5 = bit 0 + bit 2 set.
+        // M512 → coil 512 → cell 32 bit 0 = 1 (ON).
+        var addr = MelsecAddress.MRelayToCoil("M512");
+        addr.ShouldBe((ushort)512);
+
+        await using var driver = await NewDriverAsync(
+            new ModbusTagDefinition("M512",
+                ModbusRegion.Coils, Address: addr,
+                DataType: ModbusDataType.Bool, Writable: false));
+
+        var r = await driver.ReadAsync(["M512"], TestContext.Current.CancellationToken);
+        r[0].StatusCode.ShouldBe(0u);
+        r[0].Value.ShouldBe(true);
+    }
+
+    // --- helpers ---
+
+    private bool ShouldRun()
+    {
+        if (sim.SkipReason is not null) { Assert.Skip(sim.SkipReason); return false; }
+        if (!string.Equals(Environment.GetEnvironmentVariable("MODBUS_SIM_PROFILE"), "mitsubishi",
+                StringComparison.OrdinalIgnoreCase))
+        {
+            Assert.Skip("MODBUS_SIM_PROFILE != mitsubishi — skipping.");
+            return false;
+        }
+        return true;
+    }
+
+    private async Task<ModbusDriver> NewDriverAsync(params ModbusTagDefinition[] tags)
+    {
+        var drv = new ModbusDriver(
+            new ModbusDriverOptions
+            {
+                Host = sim.Host,
+                Port = sim.Port,
+                UnitId = 1,
+                Timeout = TimeSpan.FromSeconds(2),
+                Tags = tags,
+                Probe = new ModbusProbeOptions { Enabled = false },
+            },
+            driverInstanceId: "melsec-quirk");
+        await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+        return drv;
+    }
+}