feat(tui): update status bar with Tab format hint

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

crates/tui/src/ui.rs

@@ -38,7 +38,7 @@ pub fn render(frame: &mut ratatui::Frame, app: &mut App) {
 
     // ── Status bar ─────────────────────────────────────────────────
     frame.render_widget(
-        Paragraph::new(" j/k:scroll d/u:half-page f/b:page G/gg:jump q:quit"),
+        Paragraph::new(" j/k:scroll d/u:half-page f/b:page G/gg:jump Tab:format q:quit"),
         outer[2],
     );
 }