refactor: ScadaBridge module options registration -> AddValidatedOptions; clarify De Morgan predicates

src/ZB.MOM.WW.ScadaBridge.AuditLog/Configuration/AuditLogOptionsValidator.cs

@@ -39,11 +39,15 @@ public sealed class AuditLogOptionsValidator : OptionsValidatorBase<AuditLogOpti
             $"must be >= {nameof(AuditLogOptions.DefaultCapBytes)} ({options.DefaultCapBytes}); " +
             "the error-row cap is intended to capture more detail than the happy-path summary.");
 
+        // Valid when RetentionDays is within [Min, Max] inclusive. The De Morgan'd
+        // guard !(below Min OR above Max) is equivalent to (>= Min AND <= Max).
         builder.RequireThat(
             !(options.RetentionDays < MinRetentionDays || options.RetentionDays > MaxRetentionDays),
             $"AuditLog:{nameof(AuditLogOptions.RetentionDays)} ({options.RetentionDays}) " +
             $"must be in [{MinRetentionDays}, {MaxRetentionDays}] days.");
 
+        // Valid when InboundMaxBytes is within [Min, Max] inclusive. The De Morgan'd
+        // guard !(below Min OR above Max) is equivalent to (>= Min AND <= Max).
         builder.RequireThat(
             !(options.InboundMaxBytes < MinInboundMaxBytes || options.InboundMaxBytes > MaxInboundMaxBytes),
             $"AuditLog:{nameof(AuditLogOptions.InboundMaxBytes)} ({options.InboundMaxBytes}) " +

src/ZB.MOM.WW.ScadaBridge.AuditLog/ServiceCollectionExtensions.cs

@@ -3,7 +3,7 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Configuration;
 using ZB.MOM.WW.ScadaBridge.AuditLog.Central;
 using ZB.MOM.WW.ScadaBridge.AuditLog.Configuration;
 using ZB.MOM.WW.ScadaBridge.AuditLog.Payload;
@@ -62,10 +62,12 @@ public static class ServiceCollectionExtensions
         ArgumentNullException.ThrowIfNull(config);
 
         // M1: top-level AuditLogOptions + validator (redaction policy, payload caps, etc.).
-        services.AddOptions<AuditLogOptions>()
+        // Collapsed onto the shared ZB.MOM.WW.Configuration helper: it binds the
-            .Bind(config.GetSection(ConfigSectionName))
+        // "AuditLog" section, registers the validator, and enables ValidateOnStart in
-            .ValidateOnStart();
+        // one call. Same section path as before; AddAuditLog is call-once per
-        services.AddSingleton<IValidateOptions<AuditLogOptions>, AuditLogOptionsValidator>();
+        // collection, and the helper's TryAddEnumerable is idempotent for the
+        // validator (a strict improvement over the previous AddSingleton).
+        services.AddValidatedOptions<AuditLogOptions, AuditLogOptionsValidator>(config, ConfigSectionName);
 
         // M5 Bundle A: payload filter — truncates oversized RequestSummary /
         // ResponseSummary / ErrorDetail / Extra fields between event

src/ZB.MOM.WW.ScadaBridge.HealthMonitoring/HealthMonitoringOptionsValidator.cs

@@ -35,6 +35,12 @@ public sealed class HealthMonitoringOptionsValidator : OptionsValidatorBase<Heal
             $"ScadaBridge:HealthMonitoring:CentralOfflineTimeout must be a positive duration " +
             $"(was {options.CentralOfflineTimeout}).");
 
+        // Valid when CentralOfflineTimeout >= OfflineTimeout (both already
+        // required to be positive above). The De Morgan'd guard !(both positive
+        // AND Central < Offline) is true unless BOTH timeouts are positive and
+        // Central is strictly smaller — so it stays silent when either field is
+        // non-positive, leaving that failure to the dedicated positive-duration
+        // checks above rather than double-firing here.
         builder.RequireThat(
             !(options.OfflineTimeout > TimeSpan.Zero
               && options.CentralOfflineTimeout > TimeSpan.Zero