feat(chat): handle credit-gated send responses

src/app/chat/chat-screen.helpers.ts

@@ -84,8 +84,26 @@ export function getChatPaywallSubscriptionUrl(): string {
   });
 }
 
-export function getChatPaywallNavigationUrl(loginStatus: LoginStatus): string {
-  const subscriptionUrl = getChatPaywallSubscriptionUrl();
+export function getChatCreditsTopUpSubscriptionUrl(): string {
+  return ROUTE_BUILDERS.subscription("topup", {
+    returnTo: "chat",
+  });
+}
+
+export function getInsufficientCreditsSubscriptionType(
+  isVip: boolean,
+): "vip" | "topup" {
+  return isVip ? "topup" : "vip";
+}
+
+export function getChatPaywallNavigationUrl(
+  loginStatus: LoginStatus,
+  type: "vip" | "topup" = "vip",
+): string {
+  const subscriptionUrl =
+    type === "topup"
+      ? getChatCreditsTopUpSubscriptionUrl()
+      : getChatPaywallSubscriptionUrl();
   if (deriveIsGuest(loginStatus)) {
     return ROUTE_BUILDERS.authWithRedirect(subscriptionUrl);
   }