Adds the user-facing half of the beta-gate: a page at /waitlist that
the CP auth callback redirects users to when their email isn't on
the allowlist. Collects email + optional name + use-case and POSTs
to /cp/waitlist/request (backend landed in controlplane #150).
## Behavior
- No auto-pre-fill of email from URL query (CP's #145 dropped the
?email= param for the privacy reason; this test guards against a
future regression on the client side).
- Client-side validates email shape for instant feedback; backend
re-validates.
- Three UI states after submit:
success → "your request is in" banner, form hidden
dedup → softer "already on file" banner when backend returns
dedup=true (same 200, no 409 to avoid enumeration)
error → inline banner with backend message or network fallback
## Tests
9 tests in __tests__/waitlist-page.test.tsx covering:
- default render + a11y (role=button, role=status, role=alert)
- URL-pre-fill privacy regression guard
- HTML5 + JS validation (empty, malformed)
- successful POST with trimmed body
- dedup branch
- non-2xx with + without error field
- network rejection
Follow-up to the beta-gate rollout on controlplane #145 / #150.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
b7149c5dda