Agent Skills: fa-product-validation

Provides Stage 4 validation guidance for consumer one-off / in-app-purchase products - framing falsifiable money hypotheses under a cost ceiling, IP/trademark/name/domain clearance, problem and solution interviews that probe real past spend, concept tests with a clickable paywall, deflated willingness-to-pay (Van Westendorp, conjoint/MaxDiff), fake-door and painted-price tests, landing-page commitment ladders, ad-creative CPI testing that replaces the placeholder CAC, and community pre-validation. Use to get a go/no-go with at least one money-on-the-line signal before building.