fix(code-review): resolve Batch 2 open findings (AbCip, AbLegacy, Galaxy, FOCAS)

- Driver.AbCip.Contracts-001: parse 'writable' from TagConfig JSON (default true) instead of hardcoding
- Driver.AbCip.Contracts-002/-003: Dt type comment; drop dead [Display]/[Range] annotations
- Driver.AbCip.Contracts-004: dedicated AbCipEquipmentTagParser test class (+15)
- Driver.AbCip-017: document Tick severity Low-fallback on Bad severity read
- Driver.AbLegacy.Contracts-002/-003/-004: isArray-scalar remarks (+tests), MaxTagBytes/ForFamily docs
- Driver.Galaxy.Browser-003 + Driver.Galaxy.Contracts-003: extract ResolveApiKey -> GalaxySecretRef (dedup)
- Driver.Galaxy-019: cache buffered-interval only on Ok + ILogger warnings + ClassifyIntervalReply (+tests)
- Driver.FOCAS.Contracts-002: thread WriteIdempotent through DiscoverAsync (+test)

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

@@ -1,5 +1,3 @@
-using System.ComponentModel.DataAnnotations;
-
 namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip;
 
 /// <summary>
@@ -81,8 +79,7 @@ public sealed class AbCipDriverOptions
     ///     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.
     /// </summary>
-    [Display(Name = "Probe timeout (seconds)", Description = "Connection test timeout. Default 5s.", GroupName = "Diagnostics")]
-    [Range(1, 60)]
+    /// <remarks>Valid range: 1–60 seconds; the AdminUI clamps to 60s server-side.</remarks>
     public int ProbeTimeoutSeconds { get; init; } = 5;
 }