Implement send_otp and send_msg handlers with server-side validation,
captcha verification, OTP generation/verification, rate limiting,
session-backed multi-step flow, and SMS gateway integration.
Replace broken contact endpoint and types with Astro server actions;
delete endpoints/contact.ts, types/ContactForm.ts and
src/components/ContactForm.astro. Update pages/contact.astro to use
astro:actions and improve captcha handling (listen for solve and set
hidden input). Adjust OTP timing (step 60s → 300s, VALID_PAST_OTP_STEPS
5 → 1). Add validator, @types/validator, Prettier and
prettier-plugin-astro; include .prettierrc.mjs in tsconfig include.
Add Prettier config for Astro
