fix(webapp): tidy Usage page credits display

Label the Usage page credits panel "Credits" instead of "Promo credits", so
it reads correctly for any credit source (not just promo-code redemptions).

Stop showing the "Included usage" allowance for Enterprise organizations:
Enterprise inherits the Pro plan's includedUsage, but enterprise orgs bill
against prepaid credits rather than a per-month included-usage tier, so the
marker was misleading.

Author: matt-aitken

.server-changes/usage-page-credits-display.md

@@ -0,0 +1,6 @@
+---
+area: webapp
+type: fix
+---
+
+The Usage page credits panel is now labelled "Credits" (previously "Promo credits"), and the "Included usage" allowance is no longer shown for Enterprise organizations, which bill against prepaid credits rather than a per-month included-usage tier.

apps/webapp/app/routes/_app.orgs.$organizationSlug.settings.usage/route.tsx

@@ -114,6 +114,9 @@ export default function Page() {
   const currentPlan = useCurrentPlan();
   const billingLimit = useBillingLimit();
   const planLimitCents = currentPlan?.v3Subscription?.plan?.limits.includedUsage ?? 0;
+  // Enterprise bills against prepaid credits, not a per-month included-usage tier,
+  // so the "Included usage" marker doesn't apply.
+  const isEnterprise = currentPlan?.v3Subscription?.plan?.type === "enterprise";
   const billingLimitDollars = isCurrentMonth
     ? getUsageBarBillingLimitDollars(billingLimit, planLimitCents)
     : undefined;
@@ -157,7 +160,7 @@ export default function Page() {
               <div className="flex flex-col gap-1 border-t border-grid-dimmed p-3">
                 <div className="flex items-end gap-8">
                   <div className="flex flex-col gap-1">
-                    <Header2 className="whitespace-nowrap">Promo credits</Header2>
+                    <Header2 className="whitespace-nowrap">Credits</Header2>
                     <p className="whitespace-nowrap text-3xl font-medium text-text-bright">
                       {formatCurrency(promoCredits.remainingCents / 100, false)}
                     </p>
@@ -215,7 +218,9 @@ export default function Page() {
                       <UsageBar
                         current={usage.overall.current}
                         isPaying={currentPlan?.v3Subscription?.isPaying ?? false}
-                        tierLimit={isCurrentMonth ? planLimitCents / 100 : undefined}
+                        tierLimit={
+                          isCurrentMonth && !isEnterprise ? planLimitCents / 100 : undefined
+                        }
                         billingLimit={billingLimitDollars}
                       />
                     </div>