fix: cart email/phone capture form was never rendered

recordOrder() and autoSubmitPurchase() read userEmail()/userPhone()
signals and submitEmail() was fully implemented (validation, error
handling), but the success screen's template never rendered the
inputs - so the form was unreachable and the fallback auto-submit
always sent blank email/phone.

- Added the email/phone form to the payment-success screen, wired to
  the existing signals/handlers.
- autoSubmitPurchase() (the 5s fallback if the user doesn't submit
  manually) no longer navigates home via an unconditional setTimeout(0)
  fired before the submission result is known - it now waits for
  submitPurchaseEmail() to settle, same as the manual path, and skips
  entirely if the user already submitted (new purchaseSubmitted flag).
- It also now sends whatever the user has typed instead of
  hardcoded-blank fields, and shows a toast instead of only logging to
  console when no Telegram user id is available.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/translations.ts

@@ -121,6 +121,9 @@ export interface Translations {
     emailNeedsAt: string;
     emailNeedsDomain: string;
     emailInvalid: string;
+    telegramIdMissing: string;
+    emailPlaceholder: string;
+    phonePlaceholder: string;
     loginRequired: string;
     loginRequiredDesc: string;
     loginWithTelegram: string;