Move PCM decoding into a producer thread that feeds an mpsc channel,
letting the render loop drain samples non-blockingly each frame. Add a
frame-aligned sleep via event::poll to replace the implicit CPU yield
that the old blocking read provided. Also replace powf(0.5) with sqrt().
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
ncurses-rs is broken on Arch Linux ARM (missing TRUE constant in
generated bindings) and the git HEAD version breaks Ubuntu too.
crossterm is pure Rust with no C dependency, eliminating the issue
on all platforms.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
bl
