feat(focas): real FANUC 30i/31i-B PDU-v3 support (live-validated on a 31i-B)

First real FOCAS hardware contact (Makino Pro 5 / 31i-B @ 10.201.31.5). A full
v3 data-PDU capture corrected the initial diagnosis: the v3 block envelope is
identical to v1, so only specific payload structs / request math / one client
robustness gap were wrong — not "framing rewrites".

Fixes (all re-validated live through the fixed driver):
- version gate: accept inbound PDU {1,3}, keep emitting v1 (FocasWireProtocol).
- cnc_rdtimer: 8-byte {minute,msec} payload is little-endian (ParseTimer) — the
  only decode with an in-range msec field.
- pmc_rdpmcrng: request range widened to the data-type byte width
  (end = start + width - 1) so a Word/Long isn't truncated to 0 values
  (was spurious BadOutOfRange); decode extracted to ParsePmcRange.
- cnc_rdsvmeter: per-axis LOADELM is 8 bytes (not 12) and names come from the
  0x0089 block — ParseServoMeters fixes the misaligned 655360 garbage. Also the
  "hang" was NetworkStream.ReadAsync not aborting a stalled socket: ReadExactlyAsync
  now disposes the stream on cancellation so a stalled peer can't wedge a poll loop.
- cnc_rddynamic2: contract guard rejecting axis < 1 (driver poll already 1-based).
- FocasDriverProbe: run a real wire session (initiate + cnc_statinfo) instead of
  degrading to Ok=true "TCP reachability only" when FWLIB is absent — a bare TCP
  listener no longer reports HEALTHY.

cnc_rdparam (0x000e) is unsupported on this control — EW_FUNC across 14
request-framing variants x 4 known-present params; needs a reference FWLIB trace
or is restricted. Deferred (deployed config uses macros, not parameters).

Tests: FOCAS suite 234 green (+16), full solution builds 0 errors. Raw v3
captures checked in under tests/.../Fixtures/v3/. Capture tools under scripts/focas/.

Docs: docs/plans/2026-06-25-focas-pdu-v3-{30i-b-support,implementation-plan}.md,
docs/drivers/FOCAS.md, docs/v2/focas-version-matrix.md,
docs/deployments/wonder-app-vd03-makino-z-34184.md.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/FocasWireProtocolTests.cs

@@ -107,6 +107,36 @@ public sealed class FocasWireProtocolTests
         finally { client.Dispose(); server.Dispose(); }
     }
 
+    // The 10-byte header framing is identical across supported versions (only the version field
+    // differs) — older controls + the mock answer v1, modern controls answer v3 (FANUC 30i-B).
+    // Validated live 2026-06-25; see docs/plans/2026-06-25-focas-pdu-v3-30i-b-support.md.
+    [Theory]
+    [InlineData((ushort)1)]
+    [InlineData((ushort)3)]
+    public async Task ReadPduAsync_accepts_supported_version(ushort version)
+    {
+        var body = new byte[] { 9, 8, 7 };
+        var pdu = new byte[10 + body.Length];
+        new byte[] { 0xa0, 0xa0, 0xa0, 0xa0 }.CopyTo(pdu, 0);
+        BinaryPrimitives.WriteUInt16BigEndian(pdu.AsSpan(4, 2), version);
+        pdu[6] = FocasWireProtocol.TypeData;
+        pdu[7] = FocasWireProtocol.DirectionResponse;
+        BinaryPrimitives.WriteUInt16BigEndian(pdu.AsSpan(8, 2), (ushort)body.Length);
+        body.CopyTo(pdu.AsSpan(10));
+
+        var (client, server) = await ConnectedPairAsync();
+        try
+        {
+            await server.GetStream().WriteAsync(pdu);
+            var read = await FocasWireProtocol.ReadPduAsync(client.GetStream(), CancellationToken.None);
+
+            read.Type.ShouldBe(FocasWireProtocol.TypeData);
+            read.Direction.ShouldBe(FocasWireProtocol.DirectionResponse);
+            read.Body.ShouldBe(body);
+        }
+        finally { client.Dispose(); server.Dispose(); }
+    }
+
     // ---- BuildRequestBody framing ----
 
     [Fact]