docs(ab): final review r2 m4/m5 — AbCipTransport doc names Native as default; AbLegacy array-write deferral scoped to libplctag

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

docs/drivers/AbLegacy.md

@@ -207,7 +207,7 @@ down during normal dev.
 
 **Live-verify** — integration-fixture-gated (requires the AB Legacy Docker fixture).
 
-**Deferrals** — array *writes*, multi-dimensional arrays, per-element historization.
+**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).
 
 See [Uns.md §Array tags](../Uns.md#array-tags-1-d) for the cross-driver coverage matrix

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.Contracts/AbCipTransport.cs

@@ -6,9 +6,9 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip;
 /// </summary>
 public enum AbCipTransport
 {
-    /// <summary>The libplctag-backed transport. The default.</summary>
+    /// <summary>The libplctag-backed transport. The fallback; selected explicitly or via the node-level <c>Drivers:AbCip:DefaultTransport</c>.</summary>
     Libplctag,
 
-    /// <summary>The native managed EtherNet/IP + CIP transport (shared Driver.Ab.Transport stack).</summary>
+    /// <summary>The native managed EtherNet/IP + CIP transport (shared Driver.Ab.Transport stack). The default.</summary>
     Native,
 }