feat(claudbg-8bs3): highlight selected agent row with REVERSED style instead of '>' cursor

Replace the '>' prefix + yellow fg on the selected/viewing agent row with
Modifier::REVERSED applied to the full span, matching ratatui Table highlight
conventions and removing the need for a cursor character.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.beans/claudbg-8bs3--tui-color-highlight-selected-agent-row-instead-of.md

@@ -1,10 +1,11 @@
 ---
 # claudbg-8bs3
 title: 'TUI: color-highlight selected agent row instead of ''>'' cursor'
-status: todo
+status: in-progress
 type: feature
+priority: normal
 created_at: 2026-04-01T06:11:10Z
-updated_at: 2026-04-01T06:11:10Z
+updated_at: 2026-04-01T06:15:41Z
 ---
 
 In the sub-agents panel (transcript screen), the currently selected/viewed agent is shown with a '>' prefix and yellow text. Instead, use row-level color highlighting (e.g. reversed or bold style on the full row) so the cursor character is not needed — matching how ratatui Table highlights work.\n\nThe rendering is in the subagent_lines iterator in src/tui/screens/transcript.rs. Replace the '> {short_id}  {agent_type}' format with '  {short_id}  {agent_type}' and apply a highlight style (e.g. Modifier::REVERSED) to the selected row span instead.

src/tui/screens/transcript.rs

@@ -505,13 +505,14 @@ pub fn render_transcript(f: &mut Frame, area: Rect, state: &AppState) {
                 );
                 let is_panel_selected =
                     i == state.subagent_selected && state.focus == Focus::SubagentsPanel;
+                let text = format!("  {short_id}  {agent_type}");
                 if is_viewing || is_panel_selected {
                     Line::from(Span::styled(
-                        format!("> {short_id}  {agent_type}"),
-                        Style::default().fg(Color::Yellow),
+                        text,
+                        Style::default().add_modifier(Modifier::REVERSED),
                     ))
                 } else {
-                    Line::from(format!("  {short_id}  {agent_type}"))
+                    Line::from(text)
                 }
             })
             .collect()