perf(abcip): bounded-parallel tag reads (MaxConcurrentReads, default 8)

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

@@ -82,6 +82,18 @@ public sealed class AbCipDriverOptions
     /// </summary>
     public bool EnableDeclarationOnlyUdtGrouping { get; init; }
 
+    /// <summary>
+    ///     Upper bound on how many planned read work items (whole-UDT groups + per-tag fallbacks)
+    ///     one <c>ReadAsync</c> batch may have in flight against the controller at once. Bounds
+    ///     concurrency ACROSS tags only — the per-tag runtime lock (05/STAB-4) still serialises
+    ///     Read → GetStatus → Decode against any one cached libplctag handle, so the same tag
+    ///     requested twice in a batch never overlaps itself. Raising it lets libplctag overlap
+    ///     device round trips (the whole point: a strictly sequential batch pays one full round
+    ///     trip per tag); lowering it to <c>1</c> restores strictly sequential reads. Values below
+    ///     <c>1</c> are clamped to <c>1</c> at the use site.
+    /// </summary>
+    public int MaxConcurrentReads { get; init; } = 8;
+
     /// <summary>
     ///     Timeout for the AdminUI Test Connect probe, in seconds. The AdminUI clamps to a
     ///     60s server-side maximum; this default is what the form pre-fills for new instances.