Add auto-summary settings

internal/app/tabbar.go

@@ -8,9 +8,9 @@ import (
 	"unicode/utf8"
 )
 
-// Two-row tab bar: labels row, underline row. The PTY viewport's top
+// Three-row tab bar: labels row, active-thread summary row, underline row. The PTY viewport's top
 // row is therefore mainTop == tabBarRows + 1.
-const tabBarRows = 2
+const tabBarRows = 3
 
 // drawTabBar renders the top tab strip across the full host width.
 // Tabs share the available width with a flex layout — each visible
@@ -139,7 +139,8 @@ func (st *uiState) drawTabBar() {
 	}
 
 	var b strings.Builder
-	// Clear both rows so a stale label from the previous frame can't
+	// Clear all tab-bar rows so stale labels or summaries from the
+	// previous frame can't
 	// bleed through. Use ECH clamped to `width` (= childCols) instead of
 	// `\x1b[2K`: 2K wipes the entire line including the sidebar columns,
 	// and if drawSidebar's chrome cache is fresh it won't repaint to
@@ -147,6 +148,7 @@ func (st *uiState) drawTabBar() {
 	// and content should be.
 	fmt.Fprintf(&b, "\x1b[1;1H\x1b[%dX", width)
 	fmt.Fprintf(&b, "\x1b[2;1H\x1b[%dX", width)
+	fmt.Fprintf(&b, "\x1b[3;1H\x1b[%dX", width)
 
 	for _, t := range tabs {
 		// Row 1: centre-ish label inside the tab cell.
@@ -170,9 +172,9 @@ func (st *uiState) drawTabBar() {
 		b.WriteString(strings.Repeat(" ", rightPad))
 		b.WriteString(styleReset)
 
-		// Row 2: underline. Thick accent for the active tab, faint
+		// Row 3: underline. Thick accent for the active tab, faint
 		// border for the rest.
-		fmt.Fprintf(&b, "\x1b[2;%dH", t.startCol)
+		fmt.Fprintf(&b, "\x1b[3;%dH", t.startCol)
 		if t.active {
 			b.WriteString(styleAccent)
 			b.WriteString(strings.Repeat("━", t.width))
@@ -189,10 +191,14 @@ func (st *uiState) drawTabBar() {
 		fmt.Fprintf(&b, "\x1b[1;%dH %s%s%s ", hintCol, styleDim, newHint, styleReset)
 		// Underline continues faintly under the hint so the strip
 		// reads as one bar.
-		fmt.Fprintf(&b, "\x1b[2;%dH%s%s%s",
+		fmt.Fprintf(&b, "\x1b[3;%dH%s%s%s",
 			hintCol, styleBorder, strings.Repeat("─", newHintW), styleReset)
 	}
 
+	if summary := st.activeSummaryText(width - 2); summary != "" {
+		fmt.Fprintf(&b, "\x1b[2;1H %s%s%s", styleDim, summary, styleReset)
+	}
+
 	frame := b.String()
 	st.chromeCacheMu.Lock()
 	if frame == st.tabBarCache {