Add project files.

JSMR.Infrastructure/Data/Repositories/Circles/CircleLookup.cs

@@ -0,0 +1,22 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace JSMR.Infrastructure.Data.Repositories.Circles;
+
+internal static class CircleLookup
+{
+    public static async Task<int?> ResolveCircleIdAsync(AppDbContext context, int? circleId, string? nameOrMakerId, CancellationToken cancellationToken)
+    {
+        if (circleId.HasValue)
+            return circleId.Value;
+
+        if (!string.IsNullOrWhiteSpace(nameOrMakerId))
+        {
+            return await context.Circles
+                .Where(c => c.Name == nameOrMakerId || c.MakerId == nameOrMakerId)
+                .Select(c => (int?)c.CircleId)
+                .FirstOrDefaultAsync(cancellationToken);
+        }
+
+        return null;
+    }
+}