chore: [PM-29055] remove pm-25379-use-new-organization-metadata-structure feature flag (#6966)

Remove the fully-released feature flag and clean up the old code path:
- Remove flag constant from FeatureFlagKeys
- Remove [RequireFeature] gate from VNext billing controllers
- Remove old GetMetadataAsync endpoint from OrganizationBillingController
- Remove GetMetadata from IOrganizationBillingService and implementation
- Remove IsOnSecretsManagerStandalone private helper
- Remove associated tests

src/Core/Billing/Organizations/Services/IOrganizationBillingService.cs

@@ -26,13 +26,6 @@ public interface IOrganizationBillingService
     /// </example>
     Task Finalize(OrganizationSale sale);
 
-    /// <summary>
-    /// Retrieve metadata about the organization represented bsy the provided <paramref name="organizationId"/>.
-    /// </summary>
-    /// <param name="organizationId">The ID of the organization to retrieve metadata for.</param>
-    /// <returns>An <see cref="OrganizationMetadata"/> record.</returns>
-    Task<OrganizationMetadata?> GetMetadata(Guid organizationId);
-
     /// <summary>
     /// Updates the provided <paramref name="organization"/>'s payment source and tax information.
     /// If the <paramref name="organization"/> does not have a Stripe <see cref="Stripe.Customer"/>, this method will create one using the provided

src/Core/Billing/Organizations/Services/OrganizationBillingService.cs

@@ -54,52 +54,6 @@ public class OrganizationBillingService(
         }
     }
 
-    public async Task<OrganizationMetadata?> GetMetadata(Guid organizationId)
-    {
-        var organization = await organizationRepository.GetByIdAsync(organizationId);
-
-        if (organization == null)
-        {
-            return null;
-        }
-
-        if (globalSettings.SelfHosted)
-        {
-            return OrganizationMetadata.Default;
-        }
-
-        var orgOccupiedSeats = await organizationRepository.GetOccupiedSeatCountByOrganizationIdAsync(organization.Id);
-
-        if (string.IsNullOrWhiteSpace(organization.GatewaySubscriptionId))
-        {
-            return OrganizationMetadata.Default with
-            {
-                OrganizationOccupiedSeats = orgOccupiedSeats.Total
-            };
-        }
-
-        var customer = await subscriberService.GetCustomer(organization);
-
-        var subscription = await subscriberService.GetSubscription(organization, new SubscriptionGetOptions
-        {
-            Expand = ["discounts.coupon.applies_to"]
-        });
-
-        if (customer == null || subscription == null)
-        {
-            return OrganizationMetadata.Default with
-            {
-                OrganizationOccupiedSeats = orgOccupiedSeats.Total
-            };
-        }
-
-        var isOnSecretsManagerStandalone = await IsOnSecretsManagerStandalone(organization, customer, subscription);
-
-        return new OrganizationMetadata(
-            isOnSecretsManagerStandalone,
-            orgOccupiedSeats.Total);
-    }
-
     public async Task UpdatePaymentMethod(
         Organization organization,
         TokenizedPaymentSource tokenizedPaymentSource,
@@ -565,38 +519,6 @@ public class OrganizationBillingService(
         return customer;
     }
 
-    private async Task<bool> IsOnSecretsManagerStandalone(
-        Organization organization,
-        Customer? customer,
-        Subscription? subscription)
-    {
-        if (customer == null || subscription == null)
-        {
-            return false;
-        }
-
-        var plan = await pricingClient.GetPlanOrThrow(organization.PlanType);
-
-        if (!plan.SupportsSecretsManager)
-        {
-            return false;
-        }
-
-        var coupon = subscription.Discounts?.FirstOrDefault(discount =>
-            discount.Coupon?.Id == StripeConstants.CouponIDs.SecretsManagerStandalone)?.Coupon;
-
-        if (coupon == null)
-        {
-            return false;
-        }
-
-        var subscriptionProductIds = subscription.Items.Data.Select(item => item.Plan.ProductId);
-
-        var couponAppliesTo = coupon.AppliesTo?.Products;
-
-        return subscriptionProductIds.Intersect(couponAppliesTo ?? []).Any();
-    }
-
     private async Task UpdateMissingPaymentMethodBehaviourAsync(Organization organization)
     {
         var subscription = await subscriberService.GetSubscriptionOrThrow(organization);

src/Core/Constants.cs

@@ -182,7 +182,6 @@ public static class FeatureFlagKeys
 
     /* Billing Team */
     public const string TrialPayment = "PM-8163-trial-payment";
-    public const string PM25379_UseNewOrganizationMetadataStructure = "pm-25379-use-new-organization-metadata-structure";
     public const string PM24032_NewNavigationPremiumUpgradeButton = "pm-24032-new-navigation-premium-upgrade-button";
     public const string PM23713_PremiumBadgeOpensNewPremiumUpgradeDialog = "pm-23713-premium-badge-opens-new-premium-upgrade-dialog";
     public const string PM26793_FetchPremiumPriceFromPricingService = "pm-26793-fetch-premium-price-from-pricing-service";