diff --git a/src/KArtSell.Host/Program.cs b/src/KArtSell.Host/Program.cs
index 991e5c9c..a51e4a73 100644
--- a/src/KArtSell.Host/Program.cs
+++ b/src/KArtSell.Host/Program.cs
@@ -161,10 +161,7 @@ builder.Services.AddAuthorization();
 builder.Services.AddSignalR();
 builder.Services.AddSignalEngineModule();
 builder.Services.AddModelOperationsModule();
-builder.Services.AddFastEndpoints(config =>
-{
-    config.SerializerOptions.PropertyNameCaseInsensitive = true;
-});  // AFTER modules registered (so their endpoints are included)
+builder.Services.AddFastEndpoints();  // AFTER modules registered (so their endpoints are included)
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 
diff --git a/src/KArtSell.Modules.ModelOperations/ShadowRun/Sql.cs b/src/KArtSell.Modules.ModelOperations/ShadowRun/Sql.cs
index fa07c3d3..b02c44ab 100644
--- a/src/KArtSell.Modules.ModelOperations/ShadowRun/Sql.cs
+++ b/src/KArtSell.Modules.ModelOperations/ShadowRun/Sql.cs
@@ -53,6 +53,7 @@ public sealed class ShadowRunQueries(IDbConnectionFactory connectionFactory)
     /// <summary>
     /// Pre-insert shadow run with "Queued" status (no metrics yet).
     /// Called by InitiateShadowRunHandler to enable immediate polling.
+    /// Dapper: Convert DateOnly to string for SQL parameter (Dapper limitation).
     /// </summary>
     public async Task InsertShadowRunQueuedAsync(
         Guid runId,
@@ -65,7 +66,7 @@ public sealed class ShadowRunQueries(IDbConnectionFactory connectionFactory)
         const string sql = """
             insert into model_operations.shadow_run
             (run_id, model_id, window_start, window_end, status, created_at)
-            values (@RunId, @ModelId, @WindowStart, @WindowEnd, @Status, @CreatedAt)
+            values (@RunId, @ModelId, @WindowStart::date, @WindowEnd::date, @Status, @CreatedAt)
             """;
 
         await using var connection = await connectionFactory.OpenAsync(cancellationToken);
@@ -76,8 +77,8 @@ public sealed class ShadowRunQueries(IDbConnectionFactory connectionFactory)
                 {
                     RunId = runId,
                     ModelId = modelId,
-                    WindowStart = windowStart,
-                    WindowEnd = windowEnd,
+                    WindowStart = windowStart.ToString("yyyy-MM-dd"),  // PostgreSQL: ::date cast
+                    WindowEnd = windowEnd.ToString("yyyy-MM-dd"),      // PostgreSQL: ::date cast
                     Status = "Queued",
                     CreatedAt = createdAt
                 },