many fixes and improvements - rework for modules/ and common/

feat(emailer): add Postmark and Resend providers

backend/Modules/Creators/Features/ChangeBanner.cs

@@ -0,0 +1,60 @@
+using Hutopy.Infrastructure.BlobStorage.Contracts;
+using Hutopy.Modules.Creators.Data;
+
+namespace Hutopy.Modules.Creators.Features;
+
+[PublicAPI]
+public static class ChangeBanner
+{
+    public record Request(
+        Guid CreatorId,
+        IFormFile File);
+
+    public record Response(
+        string BlobUrl);
+
+    public class Handler(
+        CreatorsDbContext context,
+        IBlobStorage blobStorage)
+        : Endpoint<Request, Response>
+    {
+        public override void Configure()
+        {
+            Post("/api/creators/{CreatorId}/banner");
+            Options(o => o.WithTags("Creators"));
+            AllowFileUploads();
+        }
+
+        public override async Task HandleAsync(
+            Request request,
+            CancellationToken ct)
+        {
+            var creator = await context
+                .Creators
+                .SingleOrDefaultAsync(
+                    c => c.Id == request.CreatorId,
+                    cancellationToken: ct);
+
+            if (creator is null)
+            {
+                await SendNotFoundAsync(ct);
+                return;
+            }
+
+            var blobUrl = await blobStorage.UploadFileAsync(
+                ContainerNames.Creators,
+                $"{request.CreatorId}/{SubDirectoryNames.Profile}/{CommonFileNames.BannerPicture}",
+                request.File.OpenReadStream(),
+                request.File.ContentType,
+                ct);
+
+            creator.BannerUrl = $"{blobUrl}?t={DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()}";
+
+            await context.SaveChangesAsync(ct);
+
+            await SendOkAsync(
+                new Response(blobUrl),
+                ct);
+        }
+    }
+}