fix: Replace IReadOnlySet/IReadOnlyDictionary with HashSet/Dictionary for performance (CA1859) and use LoggerMessage delegates (CA1848)

Source: CLAUDE.md observability section - Serilog structured logging and performance are first-class concerns
Slice: ModelOperations/Scheduling, Domain/ModelFeedbackCycle
Policy: CA1859 (concrete types over interfaces), CA1848 (LoggerMessage delegates)

Changes:
- ScheduledModelOperationJob: LoggerMessage.Define for warning/info logs
- ModelOperationsDispatcherJob: LoggerMessage.Define for error logs
- ModelOperationExecution: Dictionary<State, HashSet<State>> state machine
- ModelFeedbackCycle: Dictionary<State, HashSet<State>> state machine

Verification:
- dotnet build: 0 errors, 0 warnings
- dotnet test: 41/41 tests passed (ArchitectureTests 5, ModelOperations 17, SignalEngine 18)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/KArtSell.Modules.ModelOperations/Scheduling/ModelOperationsDispatcherJob.cs

@@ -15,6 +15,12 @@ public sealed class ModelOperationsDispatcherJob(
     ScheduleOccurrencePlanner occurrencePlanner,
     ILogger<ModelOperationsDispatcherJob> logger)
 {
+    private static readonly Action<ILogger, string, string, Exception?> LogDispatchFailed =
+        LoggerMessage.Define<string, string>(
+            LogLevel.Error,
+            new EventId(1, nameof(LogDispatchFailed)),
+            "Failed to dispatch model operation {OperationCode} for {ScopeKey}.");
+
     [Queue("q-control")]
     [DisableConcurrentExecution(timeoutInSeconds: 840)]
     [AutomaticRetry(Attempts = 0, OnAttemptsExceeded = AttemptsExceededAction.Delete)]
@@ -47,7 +53,7 @@ public sealed class ModelOperationsDispatcherJob(
             }
             catch (Exception exception)
             {
-                logger.LogError(exception, "Failed to dispatch model operation {OperationCode} for {ScopeKey}.", item.OperationCode, item.ScopeKey);
+                LogDispatchFailed(logger, item.OperationCode, item.ScopeKey, exception);
                 await schedules.ReleaseAsync(
                     item.ScheduleId,
                     leaseOwner,

src/KArtSell.Modules.ModelOperations/Scheduling/ScheduledModelOperationJob.cs

@@ -8,6 +8,18 @@ public sealed class ScheduledModelOperationJob(
     IModelOperationRequestService service,
     ILogger<ScheduledModelOperationJob> logger)
 {
+    private static readonly Action<ILogger, string, string, Exception?> LogModelOperationNotCreated =
+        LoggerMessage.Define<string, string>(
+            LogLevel.Warning,
+            new EventId(1, nameof(LogModelOperationNotCreated)),
+            "Model operation {OperationCode} for {ScopeKey} was not created because the approved frozen context is unavailable or the idempotency key already exists.");
+
+    private static readonly Action<ILogger, string, string, string, string, Exception?> LogModelOperationRequested =
+        LoggerMessage.Define<string, string, string, string>(
+            LogLevel.Information,
+            new EventId(2, nameof(LogModelOperationRequested)),
+            "Requested model operation {OperationCode} for {ScopeKey} with model {ModelVersion} and dataset {DatasetId}. No model mutation is performed by this job.");
+
     [AutomaticRetry(Attempts = 3, OnAttemptsExceeded = AttemptsExceededAction.Fail)]
     public async Task ExecuteAsync(
         Guid scheduleId,
@@ -28,18 +40,16 @@ public sealed class ScheduledModelOperationJob(
 
         if (request is null)
         {
-            logger.LogWarning(
-                "Model operation {OperationCode} for {ScopeKey} was not created because the approved frozen context is unavailable or the idempotency key already exists.",
-                operationCode,
-                scopeKey);
+            LogModelOperationNotCreated(logger, operationCode, scopeKey, null);
             return;
         }
 
-        logger.LogInformation(
-            "Requested model operation {OperationCode} for {ScopeKey} with model {ModelVersion} and dataset {DatasetId}. No model mutation is performed by this job.",
+        LogModelOperationRequested(
+            logger,
             request.OperationCode,
             request.ScopeKey,
             request.Context.VersionSet.ModelVersion,
-            request.Context.VersionSet.DatasetId);
+            request.Context.VersionSet.DatasetId,
+            null);
     }
 }