feat(arrays): advertise AbCip/AbLegacy/TwinCAT array writes in DriverArrayWriteSupport

The Wave-2 lanes gave AbCip, AbLegacy and TwinCAT real whole-array write
encoders (review 07 U10/U9), but the capability table still listed all three
as scalar-only, so every array node materialised read-only and a client write
was BadNotWritable before it reached the driver.

Rows added, each listing only what WriteAsync encodes end to end:
- AbCip: SInt/USInt/Int/UInt/DInt/UDInt/Real/Dt/LInt/ULInt/LReal, declared
  length, not a safetyTag. BOOL/STRING/Structure arrays stay read-only.
- AbLegacy: Int/AnalogInt on N/B/A, Long on L, Float on F (file-width match),
  plain <file><n>:<word> address, <= 256 elements; not /bit, .sub, indirect,
  S:/I:/O:, nor native PLC-5.
- TwinCAT: every codec element type, declared length; not a BOOL bit-in-word
  path.
Elements convert in all three encoders, so the rows never key on an exact
node DataType (ScadaBridge int[] -> Int16 stays writable); they leave out
only node types whose elements never convert (DateTime/String over numeric,
Boolean on AbLegacy, STRING under DateTime on TwinCAT: culture-dependent).

Tests: driver-level parity for each driver (every element type x node type
plus shape cases, against the real write path), the AbLegacy parity tests
un-skipped, Core.Abstractions row tests, a composer test (three drivers
writable, refused shapes read-only), and the existing AbCip negative cases
moved to a BOOL array. Docs: Uns.md table, per-driver docs, data-plane rules.

Refs #737 #738 #739

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

docs/drivers/AbLegacy.md

@@ -304,8 +304,18 @@ N values of the declared `AbLegacyDataType`.  Maximum element count is 256 (PCCC
 limit).
 
 This closes the previously-noted limitation ("single-element addressing today") for the
-array read path.  The opt-in native transport also writes multi-element arrays (chunked); on libplctag
-array *writes* remain a follow-up.
+array read path.
+
+**Array writes (#738, review 07 U10 / r0 I3)** — on both transports, a whole-array write encodes exactly
+`arrayLength` elements at the **data file's** element width (N / B / A words, L longs, F floats). Element values
+**convert** (ScadaBridge writes `int[]` to Int16 nodes); a length mismatch or an element that overflows is
+`BadOutOfRange`, a non-numeric value `BadTypeMismatch`, before any runtime exists. Writable: `Int` / `AnalogInt` on
+an N / B / A file, `Long` on an L file, `Float` on an F file, on a plain `<file><number>:<word>` address of at most
+256 elements. These nodes stay **read-only** (`DriverArrayWriteSupport`): Bit arrays (bit-packed words), String /
+Timer / Counter / Control arrays (rejected at `FromTagConfig`), `/bit` and `.sub` addresses, a type that does not
+match its file (`BadTypeMismatch`), any PLC-5 on the native transport (writes refused before the wire), the
+`S:` / `I:` / `O:` files (libplctag refuses their translated names), and — deliberately — indirect addresses, whose
+element moves with the index word. An array deployed read-only before #738 turns writable on the next deploy.
 
 **Unit test coverage** — `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests/` covers
 the multi-element read path via the fake tag runtime.  The AB Legacy integration fixture is
@@ -313,8 +323,10 @@ down during normal dev.
 
 **Live-verify** — integration-fixture-gated (requires the AB Legacy Docker fixture).
 
-**Deferrals** — array *writes* on libplctag (the opt-in native transport writes them), multi-dimensional arrays, per-element historization.
-`arrayLength > 256` is rejected at init with an explicit error (PCCC payload cap).
+**Deferrals** — multi-dimensional arrays, per-element historization, array writes on hardware
+(`AbLegacyArrayWriteIntegrationTests` is green on `ab_server` and ready for a real controller via
+`AB_LEGACY_ARRAY_WRITE_BASE`).
+`arrayLength > 256` is clamped to 256 by the tag factory (PCCC payload cap), so such a node stays read-only.
 
 See [Uns.md §Array tags](../Uns.md#array-tags-1-d) for the cross-driver coverage matrix
 and the UI authoring flow.