Hide "Continue" button on splash screen for already-registered users

[plansombl]

Description

Currently, the eID Wallet splash screen always displays a "CONTINUE" button regardless of whether the user has already completed registration. For returning, registered users this button is unnecessary — they should be taken directly into the app (or to the login/unlock flow) without having to tap "Continue" on the welcome screen.

Reference

See screenshot above — the splash screen with the "CONTINUE" button is shown even after a user has already registered.

Acceptance Criteria

• On app launch, check whether the current user is already registered/has an existing account.
• If the user is registered, skip the splash/onboarding screen entirely and navigate directly to the appropriate screen (e.g. PIN/biometric unlock or home screen).
• If the user is not registered (first-time user), the splash screen with the "CONTINUE" button is displayed as normal.
• No regression in the onboarding flow for new users.

Desired Output (may vary)

Registered users land directly on the unlock/home screen after launching the app, with no unnecessary "CONTINUE" tap required.