Fitz language adds built-in SMTP, no external libraries needed

Fitz, a new programming language, now includes native SMTP outbound as a built-in feature, eliminating the need for external libraries like yagmail or nodemailer. The smtp.send() function is async by default and works identically in both run and build modes. This addition was driven by the needs of fitzwatch, an open-source status page built in Fitz.