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

feat(emailer): add Postmark and Resend providers

backend/Infrastructure/Payments/Stripe/Services/MembershipPaymentProcessor.cs

@@ -0,0 +1,65 @@
+using Hutopy.Infrastructure.Payments.Stripe.Configuration;
+using Hutopy.Modules.Creators.Contracts;
+using Hutopy.Modules.Memberships.Contracts;
+using Microsoft.Extensions.Options;
+using Stripe;
+using Stripe.Checkout;
+
+namespace Hutopy.Infrastructure.Payments.Stripe.Services;
+
+public class MembershipPaymentProcessor(
+    IOptions<StripeOptions> stripeOptions)
+: IMembershipPaymentProcessor
+{
+    public async Task<MembershipCheckoutSession> CreateCheckoutSessionAsync(
+        Guid userId,
+        CreatorReference creatorReference,
+        Guid tierId,
+        string priceId,
+        string successUrl,
+        string cancelUrl)
+    {
+        StripeConfiguration.ApiKey = stripeOptions.Value.SecretKey;
+
+        // Create Stripe customer for the user if not already created
+        var customerService = new CustomerService();
+        var customer = await customerService.CreateAsync(
+            new CustomerCreateOptions
+            {
+                Metadata = new Dictionary<string, string> { { "userId", userId.ToString() } }
+            });
+
+        // Create Checkout Session for the subscription
+        var sessionService = new SessionService();
+        var session = await sessionService.CreateAsync(
+            new SessionCreateOptions
+            {
+                Customer = customer.Id,
+                PaymentMethodTypes = ["card"],
+                LineItems =
+                [
+                    new SessionLineItemOptions { Price = priceId, Quantity = 1 }
+                ],
+                Mode = "subscription",
+                SubscriptionData = new SessionSubscriptionDataOptions
+                {
+                    ApplicationFeePercent = stripeOptions.Value.HutopyRate,
+                    TransferData = new SessionSubscriptionDataTransferDataOptions { Destination = creatorReference.StripeAccountId }
+                },
+                SuccessUrl = successUrl, // Redirect after successful payment
+                CancelUrl = cancelUrl, // Redirect after canceled payment
+                Metadata = new Dictionary<string, string>
+                {
+                    { "userId", userId.ToString() },
+                    { "creatorId", creatorReference.Id.ToString() },
+                    { "creatorName", creatorReference.Name },
+                    { "tierId", tierId.ToString() }
+                }
+            });
+
+        return new MembershipCheckoutSession(
+            session.Id,
+            session.Url);
+    }
+
+}