docs: sync hidden-card bootstrap minimum

docs: explain hidden-card bootstrap reserve

docs: sync public hidden-card buyer flow

docs: document payment intent execution blockers

docs: remove otp-first wording from public buyer flow

docs: sync public buyer-flow wording

docs: add account-level agent auto-approval guidance

docs: document automatic MoneyClaw account setup

docs: narrow recurring subscription guidance

docs: simplify moneyclaw buyer-flow narrative

docs: make skill guidance approval-first

docs: remove legacy visible-card public guidance

docs: sync public api overview with live docs

docs: sync compatibility header with live api contract

docs: align public narrative with intent-first flow