fix(settings): re-ask the PIN before a relocked backup merge and keep the PIN cooldown across prompts

A backup merge now asks for the PIN again right before it replaces a
playlist's locks when the app relocked during the import, instead of
relying on the answer given at the start. The wrong-PIN count and the
30-second pause move from the dialog into the lock service, so
dismissing and reopening the prompt no longer resets them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/app/services/parental-lock-prompt.service.ts

@@ -41,6 +41,7 @@ export class AppParentalLockPromptService implements ParentalLockPrompt {
             {
                 mode: request.mode,
                 verify: request.verify,
+                throttle: request.throttle,
                 titleKey: request.titleKey,
                 descriptionKey: request.descriptionKey,
             }