Rust-based CLI music visualiser

Overhaul interfaces, add configuration and improve documentation alongside some refactoring #5

Merged sigilzero.dev
targeting main from feat/docs
Merged opened by and assigned to sigilzero.dev
targeting main from feat/docs
Commits 20

docs: update the readme for the menu and audio options
feat: add audio menu
fix: clarify auto-advance timing and scope rows
feat: add auto-advance
fix: keep the playlist delete prompt out of the cursor
test: cover playlist editing and persistence
feat: edit playlists from the menu
feat: add playlist data and menu pages
fix: canonicalise scene selection and cover menu state
feat: add scene search
feat: add scene filtering and favourites
feat: add scene tags
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
ci: harden Tangled workflow for microvm
ci: add Tangled spindle workflow