Add scrolling actions and board widget

Introduce directional and scroll actions, update keybindings, add
scrollbar
state to SkirmishState, and render the board with a new BoardWidget.
Adjust CLI
defaults and layout heights accordingly.

src/app/keybindings/keybindings.rs

@@ -7,6 +7,12 @@ pub enum Action {
     Quit2,
     Up,
     Down,
+    Left,
+    Right,
+    ScrollUp,
+    ScrollDown,
+    ScrollLeft,
+    ScrollRight,
     Space,
     Enter,
     Esc,
@@ -17,6 +23,7 @@ pub enum Action {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, ValueEnum)]
 pub enum Group {
     Movement,
+    Scroll,
     Select,
     Input,
     Quit,
@@ -70,6 +77,60 @@ pub static KEYBINDINGS: &[KeyBinding] = &[
         symbol: "↓",
         description: "Down",
     },
+    KeyBinding {
+        action: Action::Left,
+        code: KeyCode::Left,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::NONE,
+        group: Group::Movement,
+        symbol: "←",
+        description: "Left",
+    },
+    KeyBinding {
+        action: Action::Right,
+        code: KeyCode::Right,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::NONE,
+        group: Group::Movement,
+        symbol: "→",
+        description: "Right",
+    },
+    KeyBinding {
+        action: Action::ScrollUp,
+        code: KeyCode::Up,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::CONTROL,
+        group: Group::Movement,
+        symbol: "Ctrl + ↑",
+        description: "Scroll Up ",
+    },
+    KeyBinding {
+        action: Action::ScrollDown,
+        code: KeyCode::Down,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::CONTROL,
+        group: Group::Movement,
+        symbol: "Ctrl + ↓",
+        description: "Scroll Down",
+    },
+    KeyBinding {
+        action: Action::ScrollLeft,
+        code: KeyCode::Left,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::CONTROL,
+        group: Group::Movement,
+        symbol: "Ctrl + ←",
+        description: "Scroll Left",
+    },
+    KeyBinding {
+        action: Action::ScrollRight,
+        code: KeyCode::Right,
+        kind: KeyEventKind::Press,
+        modifiers: KeyModifiers::CONTROL,
+        group: Group::Movement,
+        symbol: "Ctrl + →",
+        description: "Scroll Right",
+    },
     KeyBinding {
         action: Action::Space,
         code: KeyCode::Char(' '),