Precheck Profiles

W-PAY: bounded per-profile privacy/empty probe (run BEFORE charge). Returns per-profile {url, platform, private, reason}. private==True when the account is private OR has zero public posts. Probe is cheap (~$0.002/profile via SC, ~$0.005 for X) with a hard profile cap; transient failures never flag a profile as private (happy path is protected).

Link gate (2026-08-11): a post/permalink/company link is caught HERE — before the payment modal opens and before we spend a probe on it — so the customer fixes the link instead of paying for a scan of a handle nobody owns. It rides the existing per-profile {private, reason} contract, which /api/checkout/create already turns into a pre-charge 400 and the form already renders verbatim.