feat(chat): implement external browser prompt logic and update tests

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

@@ -8,6 +8,7 @@ export interface ExternalBrowserPromptState {
   hasInitialized: boolean;
   isLoading: boolean;
   loginStatus: LoginStatus;
+  isInAppBrowser?: boolean;
 }
 
 export type InsufficientCreditsAction = "auth" | "topup";
@@ -63,11 +64,12 @@ export function shouldStartExternalBrowserPrompt({
   hasInitialized,
   isLoading,
   loginStatus,
+  isInAppBrowser = BrowserDetector.isInAppBrowser(),
 }: ExternalBrowserPromptState): boolean {
   if (!hasInitialized || isLoading) return false;
   return (
     isChatDevelopmentEnvironment() ||
-    (loginStatus === "facebook" && BrowserDetector.isInAppBrowser())
+    (loginStatus === "facebook" && isInAppBrowser)
   );
 }