Rename GameStates to States and adjust keybindings

Replace the old `GameStates` struct with a new `states` module, rename
the
field in `App` to `states`, and update construction to pass CLI args.
Remove the now‑unused `game_states.rs` file and adjust imports
accordingly.
Update keybinding definitions: change the wildcard symbol to "[All]" and
simplify the wildcard detection logic by dropping the modifiers check.

src/app/mod.rs

@@ -1,14 +1,14 @@
 pub mod app;
-pub mod game_states;
 pub mod keybind;
 pub mod keybindings;
+pub mod states;
 pub mod view;
 pub mod views;
 pub mod widgets;
 
 pub use app::{App, Event, GameMode, PerkDecks, handle_input_events};
-pub use game_states::{
+pub use keybind::handle_keybindings;
+pub use states::{
     GameStates, MainMenuState, PerkDecksState, SettingsState, SkillsConfigState, SkirmishState,
 };
-pub use keybind::handle_keybindings;
 pub use view::View;