When prompting for a password, properly inform the terminal

[oliverpool]

Is your feature request related to a problem? Please describe.

Some terminals like ghostty or iTerm have specific security features when they identify that a password is being requested.
See ghostty-org/ghostty#3980. The lock shown in the screencast is the goal of this feature request (it prevent focus stealing I think).

Describe the solution you'd like

Either adjust the textinput or create a new passwordinput package to handle this usecase.

Describe alternatives you've considered

Manually performing the right syscalls (using unix.IoctlSetTermios to set ICANON maybe?).

Additional context

https://github.com/ghostty-org/ghostty/blob/1805a9cb87aa08a721575842389e426e15bbada2/src/termio/Exec.zig#L364-L366

        // We assume we're in some sort of password input if we're
        // in canonical mode and not echoing. This is a heuristic.
        const password_input = mode.canonical and !mode.echo;

[meowgorithm]

This is a good call. Two things to note here for implementors:

1. If we call unix.IoctlSetTermios we’ll likely need to invoke a Cmd since there’s IO. So maybe the feature is opt in.
2. Ideally this also works on Windows.