Drug safety check

Fast interaction warnings, pharmacist notes, and nearby stock — served from Cloudflare's edge (Workers + D1 + KV + Pages).

Add at least two drugs to check interactions. Demo: Paracetamol + Ibuprofen, or Alcohol + Lorazepam.

Turnstile not configured — set NEXT_PUBLIC_TURNSTILE_SITE_KEY for bot protection in production.