feat(chat): add promotional external entry flow

src/app/external-entry/external-entry-persist.tsx

@@ -5,8 +5,14 @@ import { useRouter } from "next/navigation";
 
 import {
   persistExternalEntryPayload,
+  resolveExternalEntryPromotionType,
   resolveExternalEntryTarget,
 } from "@/lib/navigation/external_entry";
+import {
+  clearPendingChatPromotion,
+  savePendingChatPromotion,
+} from "@/lib/navigation/chat_unlock_session";
+import { ROUTES } from "@/router/routes";
 import { Logger } from "@/utils";
 
 const log = new Logger("ExternalEntryPersist");
@@ -17,8 +23,8 @@ interface ExternalEntryPersistProps {
   psid: string | null;
   avatarUrl: string | null;
   target: string | null;
-  redirect: string | null;
-  next: string | null;
+  mode: string | null;
+  promotionType: string | null;
 }
 
 export default function ExternalEntryPersist({
@@ -27,26 +33,31 @@ export default function ExternalEntryPersist({
   psid,
   avatarUrl,
   target,
-  redirect,
-  next,
+  mode,
+  promotionType,
 }: ExternalEntryPersistProps) {
   const router = useRouter();
 
   useEffect(() => {
-    const destination = resolveExternalEntryTarget({
-      target,
-      redirect,
-      next,
+    const destination = resolveExternalEntryTarget({ target });
+    const resolvedPromotionType = resolveExternalEntryPromotionType({
+      mode,
+      promotionType,
     });
 
     void (async () => {
       try {
-        await persistExternalEntryPayload({
-          deviceId,
-          asid,
-          psid,
-          avatarUrl,
-        });
+        await Promise.all([
+          persistExternalEntryPayload({
+            deviceId,
+            asid,
+            psid,
+            avatarUrl,
+          }),
+          destination === ROUTES.chat && resolvedPromotionType
+            ? savePendingChatPromotion(resolvedPromotionType)
+            : clearPendingChatPromotion(),
+        ]);
       } catch (error) {
         log.warn("[ExternalEntryPersist] failed to persist payload", error);
       } finally {
@@ -57,9 +68,9 @@ export default function ExternalEntryPersist({
     avatarUrl,
     asid,
     deviceId,
-    next,
+    mode,
+    promotionType,
     psid,
-    redirect,
     router,
     target,
   ]);