## Summary
- Complete the frontend contract for hardened backend account deletion
(#319).
- For passwordless accounts, request a fresh deletion-specific WebAuthn
challenge and submit its serialized assertion.
- Reuse the existing passkey assertion serializer instead of duplicating
WebAuthn conversion logic.
- Accept the durable `manual_review` backend state while presenting the
existing safe failure copy.
## Verification
- Account deletion unit tests: 9/9.
- Focused ESLint passed for all four changed files.
- Node syntax checks and `git diff --check` passed.
Backend rollout flags remain default-off; this UI is inert until #319
schema checks and explicit API enablement are completed.
Jeppe B
f0e3c4812b