Protect mid-flow challenges now supported on sign-up and sign-in

Minor Changes

• Add support for Clerk Protect mid-flow SDK challenges (protect_check) on both sign-up and sign-in. (#8329) by @zourzouvillys

  When the Protect antifraud service issues a challenge, responses now carry a protectCheck field with { status, token, sdkUrl, expiresAt?, uiHints? }. Clients resolve the gate by loading the SDK at sdkUrl, executing the challenge, and submitting the resulting proof token via signUp.submitProtectCheck({ proofToken }) or signIn.submitProtectCheck({ proofToken }). The response may carry a chained challenge, which the SDK resolves iteratively.

  Sign-in adds a new 'needs_protect_check' value to the SignInStatus union. Upgrading this package is type-only and does not change runtime behavior: the server returns the new status (and the protectCheck field) only for instances where Protect mid-flow challenges have been explicitly enabled — the feature is off by default and is not enabled for existing instances by upgrading. The server additionally only emits the new status value to SDK versions that understand it, so older clients never receive an unknown status.

  If an exhaustive switch on signIn.status flags the new value after upgrading, handle it by running the challenge described by protectCheck and submitting the proof via submitProtectCheck(). Clients should treat the protectCheck field as the authoritative gate signal and fall back to the status value for defense in depth.

  The pre-built <SignIn /> and <SignUp /> components handle the gate automatically by routing to a new protect-check route that runs the challenge SDK and resumes the flow on completion.

Patch Changes

• Fix the touchSession option documentation to link directly to the Frontend API touch endpoint. (#9097) by @SarahSoutoul

• Polish the Protect check card: the loading spinner now hides while a challenge widget (e.g. Turnstile) is visible instead of spinning alongside it, only appears after a short delay so near-instant checks never flash it, and the card no longer reserves empty space above the spinner before a widget has rendered. (#9099) by @mwickett