v0.4.2

Per-site currency & in-app email delivery.

Sites can name a revenue currency — goal revenue then renders as real money (€49.99, not 49.99), plain numbers stay the default. And the ESP swap: Settings → Email delivery lets the admin point melytics at any SMTP provider (Resend, Postmark, Brevo…) with a guided form and a send-a-test-email button, because shared-host sendmail too often lands digests, alerts and password resets in spam. Reverting goes back to host sendmail, never to silent logging.