feat: add F1 key to toggle help overlay (#101)

## Summary
- Add F1 as an additional key binding (alongside ?) to toggle the
floating help menu
- Esc, q, and ctrl+c close the help overlay instead of quitting when
it's open
- Block all other keys while the help overlay is visible
- Update footer hint from "? help" to "F1/? help"

## Test plan
- [x] Press F1 to open help overlay
- [x] Press F1 again to close it
- [x] Press ? to toggle help (still works)
- [x] Press Esc to close help overlay
- [x] Press q while help is open — should close overlay, not quit
- [x] Press q while help is closed — should quit
- [x] Press other keys while help is open — should be blocked

Author: pablospe

pkg/ui/keys.go

@@ -83,8 +83,8 @@ var keys = &KeyMap{
 		key.WithHelp("i", "toggle icon style"),
 	),
 	ToggleHelp: key.NewBinding(
-		key.WithKeys("?"),
-		key.WithHelp("?", "toggle help"),
+		key.WithKeys("?", "f1"),
+		key.WithHelp("F1/?", "toggle help"),
 	),
 }
 

pkg/ui/tui.go

@@ -130,10 +130,17 @@ func (m mainModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.KeyPressMsg:
 		switch {
-		case key.Matches(msg, keys.Quit):
-			return m, tea.Quit
 		case key.Matches(msg, keys.ToggleHelp):
 			m.helpOpen = !m.helpOpen
+			return m, tea.Batch(cmds...)
+		case m.helpOpen && (key.Matches(msg, keys.Quit) || msg.Key().Code == tea.KeyEscape):
+			m.helpOpen = false
+			return m, tea.Batch(cmds...)
+		case m.helpOpen:
+			// Block all other keys while help is open
+			return m, tea.Batch(cmds...)
+		case key.Matches(msg, keys.Quit):
+			return m, tea.Quit
 		case key.Matches(msg, keys.Search):
 			m.searching = true
 			m.search.SetWidth(m.searchWidth())
@@ -471,7 +478,7 @@ func (m mainModel) footerView() string {
 	files := fmt.Sprintf(" %d files", len(m.files))
 	sep := lipgloss.NewStyle().Foreground(lipgloss.BrightBlack).Render(" • ")
 	added, deleted := m.diffViewer.RootDiffStats()
-	help := base.Background(lipgloss.BrightBlack).PaddingLeft(1).PaddingRight(1).Render("? help")
+	help := base.Background(lipgloss.BrightBlack).PaddingLeft(1).PaddingRight(1).Render("F1/? help")
 	stats := filenode.ViewDiffStats(added, deleted, base)
 	spacing := base.Render(strings.Repeat(" ", max(0, m.width-lipgloss.Width(stats)-
 		lipgloss.Width(help)-lipgloss.Width(files)-lipgloss.Width(sep))))