v2.6.0 — E-commerce blueprint + auth screens pattern

Coverage gaps from the v2.5.0 audit closed: the two most-built surfaces the library didn't cover.

Added

• blueprints/ecommerce-from-scratch.md — 10th build protocol: PLP (filters, card anatomy, pagination strategy), PDP (gallery/LCP discipline, fixed buy-box order, variant rules, sticky mobile add-to-cart), cart (real-total transparency, collapsed promo field), checkout (guest-first, one column, 12-element form budget, full autocomplete map, payment-error state), confirmation. Grounded in Baymard 2026 data: ~70% average cart abandonment — unexpected costs 48%, forced account creation 26%, checkout complexity 18%. Dark-pattern boundary restated for commerce (no fake scarcity, no drip pricing, no preselected add-ons).
• patterns/product-ui/auth-screens.md — the auth flow beyond sign-in (which stays in forms.md Pattern 1): sign-up (live requirement checklist instead of a strength meter, no confirm-password), forgot/reset (enumeration-safe messaging, direct sign-in after reset), magic link (sent-state design, resend cooldown, cross-device), OTP/2FA (one input + autocomplete="one-time-code", not six boxes), anti-pattern table.

Wired in

SKILL.md (Task Routing + blueprints enumeration + version 2.6.0), task-routing.md, CLAUDE.md, README.md (badge, blueprints tree, product-ui 12 → 13).