Refactor keybindings widget and reorder Group enum

- Introduce `KeybindingsWidget::new(view)` constructor and remove the
  standalone `keybindings_widget` function.
- Update all imports and call sites to use `KeybindingsWidget` directly.
- Reorder `Group` enum to place `Quit` after `Select` and adjust its
  iterator accordingly.

src/app/widgets/keybindings.rs

@@ -14,6 +14,43 @@ pub struct KeybindingsWidget {
     grouped: Vec<Paragraph<'static>>,
 }
 
+impl KeybindingsWidget {
+    pub fn new(view: View) -> Self {
+        let (used_groups, keybindings) = binding_for_view(view);
+
+        let mut grouped_keybindings: Vec<Paragraph<'static>> = Vec::new();
+        for (i, group) in Group::iter().enumerate() {
+            if !used_groups.contains(&group) {
+                continue;
+            }
+
+            let grouped_lines: Vec<Line<'_>> = keybindings
+                .iter()
+                .filter(|b| b.group == group)
+                .map(|b| {
+                    Line::from_iter([b.symbol.red().bold(), " - ".into(), b.description.into()])
+                })
+                .collect();
+
+            let mut block: Block<'_> = Block::default().padding(Padding::new(1, 1, 0, 0));
+
+            if i != 0 {
+                block = block.borders(Borders::LEFT);
+            }
+
+            grouped_keybindings.push(
+                Paragraph::new(grouped_lines)
+                    .alignment(Alignment::Center)
+                    .block(block),
+            );
+        }
+
+        Self {
+            grouped: grouped_keybindings,
+        }
+    }
+}
+
 impl Widget for KeybindingsWidget {
     fn render(self, area: Rect, buf: &mut Buffer) {
         let count: u16 = self.grouped.len() as u16;
@@ -41,36 +78,3 @@ impl Widget for KeybindingsWidget {
         }
     }
 }
-
-pub fn keybindings_widget(view: View) -> KeybindingsWidget {
-    let (used_groups, keybindings) = binding_for_view(view);
-
-    let mut grouped_keybindings: Vec<Paragraph<'static>> = Vec::new();
-    for (i, group) in Group::iter().enumerate() {
-        if !used_groups.contains(&group) {
-            continue;
-        }
-
-        let grouped_lines: Vec<Line<'_>> = keybindings
-            .iter()
-            .filter(|b| b.group == group)
-            .map(|b| Line::from_iter([b.symbol.red().bold(), " - ".into(), b.description.into()]))
-            .collect();
-
-        let mut block: Block<'_> = Block::default().padding(Padding::new(1, 1, 0, 0));
-
-        if i != 0 {
-            block = block.borders(Borders::LEFT);
-        }
-
-        grouped_keybindings.push(
-            Paragraph::new(grouped_lines)
-                .alignment(Alignment::Center)
-                .block(block),
-        );
-    }
-
-    KeybindingsWidget {
-        grouped: grouped_keybindings,
-    }
-}