Refactor to View enum and add keybindings

Replace the `default_window` string field with a `View` enum throughout
the
application. Introduce a new keybinding module providing `Action`,
`KeyBinding` structs and helper functions, and integrate a keybindings
widget
into the main menu. Update the CLI to accept a `View` value enum and
adjust
imports and event handling accordingly. Add a release profile in
`Cargo.toml` with LTO, single codegen unit, higher optimisation level
and
binary stripping for smaller, faster builds.

src/app/widgets/keybindings.rs

@@ -0,0 +1,31 @@
+use ratatui::{
+    crossterm::event::KeyCode,
+    layout::Alignment,
+    style::Stylize,
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+};
+
+use crate::app::{View, binding_for_view};
+
+pub fn keybindings_widget(view: View) -> Paragraph<'static> {
+    let lines: Vec<Line> = binding_for_view(view)
+        .iter()
+        .map(|b| {
+            let key_span = match b.code {
+                KeyCode::Char(c) => Span::raw(c.to_string()),
+                other => Span::raw(format!("{:?}", other)),
+            }
+            .bold()
+            .red();
+
+            Line::from_iter([key_span, "\t - ".into(), b.description.into()])
+        })
+        .collect();
+
+    Paragraph::new(lines).alignment(Alignment::Left).block(
+        Block::default()
+            .borders(Borders::ALL)
+            .title("[ Keybindings ]"),
+    )
+}

src/app/widgets/main_menu.rs

@@ -1,47 +1,42 @@
 use ratatui::{
     buffer::Buffer,
     layout::{Alignment, Constraint, Layout, Rect},
-    style::{Color, Stylize},
-    text::Line,
+    style::Color,
     widgets::{Block, Borders, Paragraph, Widget},
 };
 
+use crate::app::{View, widgets::keybindings_widget};
+
 pub fn main_menu_widget(area: Rect, buf: &mut Buffer) {
     let vertical_layout: Layout =
         Layout::vertical([Constraint::Percentage(90), Constraint::Percentage(10)]);
 
     let [main_menu_area, keybindings_area] = vertical_layout.areas(area);
 
-    let title_text: String = vec![
-        r" __    __             _         _____                        _     ",
-        r"/ / /\ \ \__ _ _ __  (_)_ __   /__   \_   _ _ __  _ __   ___| |___",
-        r"\ \/  \/ / _` | '__| | | '_ \    / /\/ | | | '_ \| '_ \ / _ \ / __|",
-        r" \  /\  / (_| | |    | | | | |  / /  | |_| | | | | | | |  __/ \__ \",
-        r"  \/  \/ \__,_|_|    |_|_| |_|  \/    \__,_|_| |_|_| |_|\___|_|___/",
-    ]
-    .join("\n");
+    {
+        let title_text: String = vec![
+            r" __    __             _         _____                        _     ",
+            r"/ / /\ \ \__ _ _ __  (_)_ __   /__   \_   _ _ __  _ __   ___| |___",
+            r"\ \/  \/ / _` | '__| | | '_ \    / /\/ | | | '_ \| '_ \ / _ \ / __|",
+            r" \  /\  / (_| | |    | | | | |  / /  | |_| | | | | | | |  __/ \__ \",
+            r"  \/  \/ \__,_|_|    |_|_| |_|  \/    \__,_|_| |_|_| |_|\___|_|___/",
+        ]
+        .join("\n");
 
-    let title: Paragraph<'_> = Paragraph::new(title_text)
-        .alignment(Alignment::Center)
-        .style(Color::Yellow)
-        .block(
-            Block::default()
-                .borders(Borders::LEFT | Borders::RIGHT | Borders::TOP)
-                .style(Color::Gray),
-        );
+        let title: Paragraph<'_> = Paragraph::new(title_text)
+            .alignment(Alignment::Center)
+            .style(Color::Yellow)
+            .block(
+                Block::default()
+                    .borders(Borders::LEFT | Borders::RIGHT | Borders::TOP)
+                    .style(Color::Gray),
+            );
 
-    title.render(main_menu_area, buf);
+        title.render(main_menu_area, buf);
+    }
 
-    let keybindings_text: Vec<Line<'_>> =
-        vec![Line::from_iter(["q".bold().red(), "\t - Quit".into()])];
-
-    let keybindings: Paragraph<'_> = Paragraph::new(keybindings_text)
-        .alignment(Alignment::Left)
-        .block(
-            Block::default()
-                .borders(Borders::ALL)
-                .title("[ Keybinding ]"),
-        );
-
-    keybindings.render(keybindings_area, buf);
+    {
+        let keybindings: Paragraph<'_> = keybindings_widget(View::MainMenu);
+        keybindings.render(keybindings_area, buf);
+    }
 }

src/app/widgets/mod.rs

@@ -1,3 +1,5 @@
+pub mod keybindings;
 pub mod main_menu;
 
+pub use keybindings::keybindings_widget;
 pub use main_menu::main_menu_widget;