Use F1 as primary help key (with Ctrl+? fallback)

- F1 is universally supported across all terminals
- Ctrl+? still works as fallback for terminals with keyboard enhancements
- Tested successfully in tmux
- Updated documentation to reflect F1 as primary binding

Assisted-By: docker-agent

Author: masegraye

docs/HELP_DIALOG.md

@@ -6,7 +6,7 @@ The cagent TUI now includes a contextual help dialog that displays all currently
 
 ## Usage
 
-Press **Ctrl+?** (Ctrl+Shift+/) to open the help dialog.
+Press **F1** to open the help dialog. (Alternatively, **Ctrl+?** also works in terminals that support keyboard enhancements.)
 
 The dialog will show all key bindings that are currently active based on:
 - Which panel is focused (content view vs editor)
@@ -61,6 +61,10 @@ newFeatureKey := key.NewBinding(
 
 The help dialog will pick this up automatically when it's included in any `Bindings()` return value.
 
+## Key Binding Notes
+
+**F1** is used as the primary help key because it's universally supported across all terminals. **Ctrl+?** (Ctrl+Shift+/) is also supported as an alternative, but requires terminals with keyboard enhancement support (kitty protocol).
+
 ## Related Files
 
 - `pkg/tui/dialog/help.go` - Help dialog implementation

pkg/tui/tui.go

@@ -1578,8 +1578,8 @@ func (m *appModel) Bindings() []key.Binding {
 	))
 
 	bindings = append(bindings, key.NewBinding(
-		key.WithKeys("ctrl+?"),
-		key.WithHelp("Ctrl+?", "help"),
+		key.WithKeys("f1"),
+		key.WithHelp("F1", "help"),
 	))
 
 	// Show newline help based on keyboard enhancement support
@@ -1693,7 +1693,7 @@ func (m *appModel) handleKeyPress(msg tea.KeyPressMsg) (tea.Model, tea.Cmd) {
 	case key.Matches(msg, key.NewBinding(key.WithKeys("ctrl+x"))):
 		return m, core.CmdHandler(messages.ClearQueueMsg{})
 
-	case key.Matches(msg, key.NewBinding(key.WithKeys("ctrl+?"))):
+	case key.Matches(msg, key.NewBinding(key.WithKeys("ctrl+?", "f1"))):
 		// Show contextual help dialog with all currently active key bindings
 		return m, core.CmdHandler(dialog.OpenDialogMsg{
 			Model: dialog.NewHelpDialog(m.Bindings()),