- square.ts: shouldFallbackTo2FA replaced by shouldShowSCARefusal — a genuine
'sca-unavailable' now drives the REFUSAL path (the customer is told the
payment cannot complete and to pay online later), never the 2FA code fallback
(PSR 2017 SCA is non-waivable; merchant liability is not cured by consent).
SCA_REFUSAL_MESSAGE_ONLINE/TILL copy added; SCA_FALLBACK_CONSENT_VERSION 'v1'
+ scaFallbackConsentFields() carry the versioned consent on the explicit
opt-in path only (shipped surfaces send none). SquareTokenizeResult docs
updated: tokenize-result token is the charge source, tokenless OK proceeds
token-less under the backend's SCA-only gate.
- C1 wire contract on every saved-card surface (booking, tip, gift-card buy,
till, account): the proactive SCA tokenize-result is sent as new_card_token
(the charge SOURCE alongside the saved-card ref), never the legacy
verification_token; 402 verification-required now means the tokenize-result
was consumed/expired between tokenize and charge.
- New ScaFallbackConsentDialog surfaces the refusal notice; the code input
(useTwoFactorCodeForSavedCard scaAvailable: () => true) only ever appears via
a backend gate rejection (defensive/opt-in).
- Till (M10): proactive saved-card SCA runs per sale line BEFORE the first
charge; sca-unavailable aborts the whole sale before any charge.
- Card save (M11/M12): STORE-intent tokenizeForStore with SCA at tokenization;
402 verification-required on save surfaces SCA-first guidance instead of a
generic failure.
