- Fix MailMailButton nil errors in SendMailFrame_CanSend and sendmail_clear
- Keep a safe reference to the original Send Mail button
- Add fallback handling for MailSubjectEditBox
- Improve compatibility with UI/mailbox modifications
- Update version to 1.4.8
- Update README and audit documentation
Validated in-game without Lua errors. Adds compatibility and safety fixes for TurtleMail on Turtle WoW 1.18.x / Octo while keeping upstream code largely intact.