2026-08-28 — Adapty web access integration

Added site-nextjs/lib/adapty-server.ts — server-side profile fetch/create and premium access-level checks via Adapty’s REST API.

Added GET /api/adapty/access for authenticated Better Auth users.

Auth provider exposes hasPaidAccess and adaptyConfigured (mobile remains on adapty_flutter).

Documented ADAPTY_SECRET_API_KEY; updated subscription and env-var docs.