App now receives an AppChannels struct; AppEvent enum removed.
Event handling, tick generation, and audio communication are now
performed through dedicated channels.
Introduce `AppEvent::Tick` and a background thread that emits timed
events. `App` now handles `Tick` by calling a new `update` method,
which advances the board and increments a `turn_counter` in
`SkirmishState`. Add required imports, fields, and the
`spawn_tick_thread` call in `main`.
The event loop function is now defined in `events.rs`, the redundant
`handle_events.rs` file is removed, and the module re‑exports are
updated
to expose `handle_events` from `events`.
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`.
GarandPLG