Add TOTP-based two-factor authentication

[piotrfx]

• Add 2FA setup, enable, disable, and backup code management
• Integrate 2FA challenge flow into login process
• Add frontend modal for 2FA configuration
• Support backup codes for account recovery

[nginxproxymanagerci]

Docker Image for build 3 is available on DockerHub:

nginxproxymanager/nginx-proxy-manager-dev:pr-5109

Note

Ensure you backup your NPM instance before testing this image! Especially if there are database changes.
This is a different docker image namespace than the official image.

Warning

Changes and additions to DNS Providers require verification by at least 2 members of the community!

[piotrfx]

Tested locally and works fine, we're adding to our production servers this modified version with 2FA as I'm not sure how quickly this can end up in the main repo ;). I've ran Claude for security checks and all is fine as well.