Update formatting to use 4‑space indentation

- Adjust rustfmt.toml to set tab_spaces = 4.
- Reformat imports, struct definitions, function bodies, and match arms
  across the project to match the new style (aligned fields, added
  spacing, etc.).
- Ensure all code complies with the updated rustfmt settings.

tests/app.rs

@@ -1,162 +1,161 @@
 use clap::Parser;
 use ratatui::{
-  Terminal,
-  backend::TestBackend,
-  crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyModifiers},
-  layout::Rect,
+    Terminal,
+    backend::TestBackend,
+    crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyModifiers},
+    layout::Rect,
 };
 use std::sync::mpsc::{Receiver, channel};
 use war_in_tunnels::{
-  app::{App, GameStates, View, handle_keybindings, threads::AudioCmd},
-  cli::Cli,
+    app::{App, GameStates, View, handle_keybindings, threads::AudioCmd},
+    cli::Cli,
 };
 
 fn app() -> (App, Receiver<AudioCmd>) {
-  let args = Cli::try_parse_from(["game", "--disable-audio"]).unwrap();
-  let (tx, rx) = channel();
-  let mut app = App::new(args, tx);
-  app.window_area = Rect::new(0, 0, 120, 40);
-  app.states = Some(GameStates::new(&app.args, &app.window_area));
-  (app, rx)
+    let args = Cli::try_parse_from(["game", "--disable-audio"]).unwrap();
+    let (tx, rx) = channel();
+    let mut app = App::new(args, tx);
+    app.window_area = Rect::new(0, 0, 120, 40);
+    app.states = Some(GameStates::new(&app.args, &app.window_area));
+    (app, rx)
 }
 
 fn press(app: &mut App, code: KeyCode) {
-  handle_keybindings(app, KeyEvent::new(code, KeyModifiers::NONE));
+    handle_keybindings(app, KeyEvent::new(code, KeyModifiers::NONE));
 }
 
 #[test]
 fn menu_selection_stays_in_bounds_and_opens_each_view() {
-  let (mut app, _) = app();
-  for _ in 0..10 {
-    press(&mut app, KeyCode::Up);
-  }
-  assert_eq!(app.states_ref().unwrap().main_menu.selected_view, 1);
-  for view in [View::Skirmish, View::PerkDecks, View::SkillsConfig] {
-    press(&mut app, KeyCode::Char(' '));
-    assert_eq!(app.view, view);
-    press(&mut app, KeyCode::Esc);
-    assert_eq!(app.view, View::MainMenu);
-    press(&mut app, KeyCode::Down);
-  }
-  for _ in 0..10 {
-    press(&mut app, KeyCode::Down);
-  }
-  assert_eq!(app.states_ref().unwrap().main_menu.selected_view, 3);
+    let (mut app, _) = app();
+    for _ in 0..10 {
+        press(&mut app, KeyCode::Up);
+    }
+    assert_eq!(app.states_ref().unwrap().main_menu.selected_view, 1);
+    for view in [View::Skirmish, View::PerkDecks, View::SkillsConfig] {
+        press(&mut app, KeyCode::Char(' '));
+        assert_eq!(app.view, view);
+        press(&mut app, KeyCode::Esc);
+        assert_eq!(app.view, View::MainMenu);
+        press(&mut app, KeyCode::Down);
+    }
+    for _ in 0..10 {
+        press(&mut app, KeyCode::Down);
+    }
+    assert_eq!(app.states_ref().unwrap().main_menu.selected_view, 3);
 }
 
 #[test]
 fn quit_keys_work_in_every_view() {
-  for view in [
-    View::MainMenu,
-    View::Skirmish,
-    View::PerkDecks,
-    View::SkillsConfig,
-  ] {
-    for key in [
-      KeyEvent::new(KeyCode::Char('q'), KeyModifiers::NONE),
-      KeyEvent::new(KeyCode::Char('c'), KeyModifiers::CONTROL),
+    for view in [
+        View::MainMenu,
+        View::Skirmish,
+        View::PerkDecks,
+        View::SkillsConfig,
     ] {
-      let (mut app, _) = app();
-      app.view = view;
-      handle_keybindings(&mut app, key);
-      assert!(app.exit);
+        for key in [
+            KeyEvent::new(KeyCode::Char('q'), KeyModifiers::NONE),
+            KeyEvent::new(KeyCode::Char('c'), KeyModifiers::CONTROL),
+        ] {
+            let (mut app, _) = app();
+            app.view = view;
+            handle_keybindings(&mut app, key);
+            assert!(app.exit);
+        }
     }
-  }
 }
 
 #[test]
 fn key_release_does_not_trigger_quit() {
-  let (mut app, _) = app();
-  handle_keybindings(
-    &mut app,
-    KeyEvent::new_with_kind(
-      KeyCode::Char('q'),
-      KeyModifiers::NONE,
-      KeyEventKind::Release,
-    ),
-  );
-  assert!(!app.exit);
+    let (mut app, _) = app();
+    handle_keybindings(
+        &mut app,
+        KeyEvent::new_with_kind(
+            KeyCode::Char('q'),
+            KeyModifiers::NONE,
+            KeyEventKind::Release,
+        ),
+    );
+    assert!(!app.exit);
 }
 
 #[test]
 fn music_keys_send_commands_without_opening_audio_device() {
-  let (mut app, rx) = app();
-  press(&mut app, KeyCode::Char('m'));
-  press(&mut app, KeyCode::Char('b'));
-  press(&mut app, KeyCode::Char('n'));
-  assert!(matches!(rx.try_recv().unwrap(), AudioCmd::Mute));
-  assert!(matches!(rx.try_recv().unwrap(), AudioCmd::VolumeUp));
-  assert!(matches!(rx.try_recv().unwrap(), AudioCmd::VolumeDown));
-  drop(rx);
-  press(&mut app, KeyCode::Char('m'));
-  assert!(!app.exit);
+    let (mut app, rx) = app();
+    press(&mut app, KeyCode::Char('m'));
+    press(&mut app, KeyCode::Char('b'));
+    press(&mut app, KeyCode::Char('n'));
+    assert!(matches!(rx.try_recv().unwrap(), AudioCmd::Mute));
+    assert!(matches!(rx.try_recv().unwrap(), AudioCmd::VolumeUp));
+    assert!(matches!(rx.try_recv().unwrap(), AudioCmd::VolumeDown));
+    drop(rx);
+    press(&mut app, KeyCode::Char('m'));
+    assert!(!app.exit);
 }
 
 #[test]
 fn skirmish_keys_move_focus_toggle_panel_and_limit_zoom() {
-  let (mut app, _) = app();
-  app.view = View::Skirmish;
-  press(&mut app, KeyCode::Right);
-  assert_eq!(
-    app
-      .states_ref()
-      .unwrap()
-      .skirmish
-      .board
-      .get_focused_cell()
-      .get_coords(),
-    (5, 4)
-  );
-  press(&mut app, KeyCode::Tab);
-  assert!(app.states_ref().unwrap().skirmish.side_panel);
-  press(&mut app, KeyCode::Tab);
-  assert!(!app.states_ref().unwrap().skirmish.side_panel);
-  for _ in 0..4 {
-    press(&mut app, KeyCode::Char(','));
-  }
-  assert_eq!(
-    app.states_ref().unwrap().skirmish.board.zoom_level,
-    war_in_tunnels::app::states::skirmish_states::ZoomLevel::ZoomedIn
-  );
-  for _ in 0..4 {
-    press(&mut app, KeyCode::Char('.'));
-  }
-  assert_eq!(
-    app.states_ref().unwrap().skirmish.board.zoom_level,
-    war_in_tunnels::app::states::skirmish_states::ZoomLevel::ZoomedOut
-  );
+    let (mut app, _) = app();
+    app.view = View::Skirmish;
+    press(&mut app, KeyCode::Right);
+    assert_eq!(
+        app.states_ref()
+            .unwrap()
+            .skirmish
+            .board
+            .get_focused_cell()
+            .get_coords(),
+        (5, 4)
+    );
+    press(&mut app, KeyCode::Tab);
+    assert!(app.states_ref().unwrap().skirmish.side_panel);
+    press(&mut app, KeyCode::Tab);
+    assert!(!app.states_ref().unwrap().skirmish.side_panel);
+    for _ in 0..4 {
+        press(&mut app, KeyCode::Char(','));
+    }
+    assert_eq!(
+        app.states_ref().unwrap().skirmish.board.zoom_level,
+        war_in_tunnels::app::states::skirmish_states::ZoomLevel::ZoomedIn
+    );
+    for _ in 0..4 {
+        press(&mut app, KeyCode::Char('.'));
+    }
+    assert_eq!(
+        app.states_ref().unwrap().skirmish.board.zoom_level,
+        war_in_tunnels::app::states::skirmish_states::ZoomLevel::ZoomedOut
+    );
 }
 
 #[test]
 fn all_views_render_without_real_terminal() {
-  let (mut app, _) = app();
-  let mut terminal = Terminal::new(TestBackend::new(120, 40)).unwrap();
-  for view in [
-    View::MainMenu,
-    View::Skirmish,
-    View::PerkDecks,
-    View::SkillsConfig,
-  ] {
-    app.view = view;
-    let before = app.states.clone();
-    terminal
-      .draw(|frame| frame.render_widget(&mut app, frame.area()))
-      .unwrap();
-    let buffer = terminal.backend().buffer();
-    let text: String = buffer.content.iter().map(|cell| cell.symbol()).collect();
-    assert!(!text.trim().is_empty(), "{view:?}");
-    if matches!(view, View::PerkDecks | View::SkillsConfig) {
-      assert!(text.contains("Work in progress"));
+    let (mut app, _) = app();
+    let mut terminal = Terminal::new(TestBackend::new(120, 40)).unwrap();
+    for view in [
+        View::MainMenu,
+        View::Skirmish,
+        View::PerkDecks,
+        View::SkillsConfig,
+    ] {
+        app.view = view;
+        let before = app.states.clone();
+        terminal
+            .draw(|frame| frame.render_widget(&mut app, frame.area()))
+            .unwrap();
+        let buffer = terminal.backend().buffer();
+        let text: String = buffer.content.iter().map(|cell| cell.symbol()).collect();
+        assert!(!text.trim().is_empty(), "{view:?}");
+        if matches!(view, View::PerkDecks | View::SkillsConfig) {
+            assert!(text.contains("Work in progress"));
+        }
+        assert_eq!(app.states, before);
     }
-    assert_eq!(app.states, before);
-  }
 }
 
 #[test]
 fn common_keys_work_before_states_are_initialized() {
-  let (mut app, _) = app();
-  app.states = None;
-  press(&mut app, KeyCode::Down);
-  press(&mut app, KeyCode::Char('q'));
-  assert!(app.exit);
+    let (mut app, _) = app();
+    app.states = None;
+    press(&mut app, KeyCode::Down);
+    press(&mut app, KeyCode::Char('q'));
+    assert!(app.exit);
 }