Rust-based CLI music visualiser

Improve menu interface #3

Closed sigilzero.dev
targeting ci/tangled from feat/menu-config
Closed opened by and assigned to sigilzero.dev
targeting ci/tangled from feat/menu-config
Commits 6

fix: open and leave menu pages with left and right
fix: keep menu and audio source selection explicit
refactor: drive settings through the menu
feat: add generic menu model
feat: add config and state files
refactor: remove status and help overlays