TECHBITFORGE-office/MailOTP-Guard ? reverse-engineered prompt

Build me a small Flask app for password free email login using one time passcodes. I want users to enter their email, get a nicely formatted OTP email, then verify the code to log in. The code should expire after 5 minutes, and there should be a resend cooldown so people cannot spam requests. Please add basic protection against brute force attempts, including temporary IP blocking after too many failures, and keep all secrets in environment variables with a .env file.

Make the email content look professional, using HTML templates, and keep the app simple enough to run locally with a single Python file. It should expose routes for sending an OTP, resending it, and verifying it, and use SMTP for email delivery. If anything needs current Flask or email library setup details, look up the latest docs online and wire it up cleanly.