Add ALSA and Rodio crates to Cargo.toml and lockfile to enable audio
playback.
Update Nix expressions to include `alsa-lib` as a build input.
Refactor input event handling into a new `app::threads` module:
- Define `AppEvent` enum and `handle_input_events` function there.
- Adjust imports in `app/app.rs` and `main.rs` accordingly.
Remove the now‑unused `handle_input_events` and `AppEvent`
definitions from
`app/app.rs`.
Extracted common quit/esc handling into `common_keybindings`. Introduced
`Group::CtrlMovement` for Ctrl‑arrow keys and updated keybinding
definitions.
Removed duplicated quit logic in main_menu and skirmish modules. Bumped
clap to 4.6.0 and updated Cargo.lock. Added range‑checked parsers for
map
size, resources, supply limit, XP modifier and skill points in the CLI.
GarandPLG