Frontend half of S-26. registration-page asks the BFF for the caller's current open
registration on init (regenerated api-client → getSelfServiceRegistrations) and
restores the submitted view — reference + the documenten/withdraw actions — instead
of dropping back to the blank form after a refresh; 204 (none) shows the form as
before. Component test covers resume-on-load; a Playwright e2e submits, reloads, and
asserts the reference + actions persist.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>