fix(tui): restore bubble modes and stabilize flame zoom lineage

3 files changed, 132 insertions, 38 deletions

diff --git a/internal/tui/flamegraph/controls.go b/internal/tui/flamegraph/controls.go
index e69d845..37b030a 100644
--- a/internal/tui/flamegraph/controls.go
+++ b/internal/tui/flamegraph/controls.go
@@ -89,7 +89,7 @@ func (m Model) toolbarLine() string {
 	if m.statusMessage != "" {
 		line += " | " + m.statusMessage
 	}
-	if m.lastKeyDebug != "" {
+	if flameKeyDebugEnabled && m.lastKeyDebug != "" {
 		line += " | " + m.lastKeyDebug
 	}
 	width := m.width
diff --git a/internal/tui/flamegraph/model.go b/internal/tui/flamegraph/model.go
index 1d01f66..9c7bac5 100644
--- a/internal/tui/flamegraph/model.go
+++ b/internal/tui/flamegraph/model.go
@@ -26,6 +26,7 @@ type snapshotNode struct {
 type animTickMsg struct{}
 
 const animFrameDuration = 33 * time.Millisecond
+const flameKeyDebugEnabled = false
 
 // LiveTrieSource is the minimal trie contract needed by the flamegraph TUI model.
 type LiveTrieSource interface {
@@ -467,7 +468,17 @@ func (m *Model) rebuildFrames(animate bool) {
 	} else {
 		root = m.snapshot
 	}
-	targetFrames := buildTerminalLayoutWithPath(root, m.width, m.height, rootPath)
+	layoutWidth := m.width
+	if m.zoomPath != "" {
+		fallbackLineWidth := m.zoomLineWidth
+		if fallbackLineWidth <= 0 {
+			fallbackLineWidth = layoutWidth
+		}
+		if _, gutter, ok := m.zoomLineageGeometry(fallbackLineWidth); ok {
+			layoutWidth = m.width - gutter
+		}
+	}
+	targetFrames := buildTerminalLayoutWithPath(root, layoutWidth, m.height, rootPath)
 	if m.zoomPath != "" {
 		targetFrames = m.withZoomLineage(targetFrames)
 	}
@@ -544,7 +555,7 @@ func (m *Model) zoomIn() {
 	m.zoomRoot = target
 	m.zoomPath = selectedPath
 	m.zoomLineWidth = selectedWidth
-	m.rebuildFrames(true)
+	m.rebuildFrames(false)
 	m.statusMessage = "Zoom: " + compactFramePath(selectedPath)
 }
 
@@ -564,7 +575,7 @@ func (m *Model) zoomUndo() {
 		m.zoomLineWidth = last.lineWidth
 	}
 	m.selectedIdx = last.previousSelectedIdx
-	m.rebuildFrames(true)
+	m.rebuildFrames(false)
 	if m.zoomPath == "" {
 		m.statusMessage = "Zoom: root"
 		return
@@ -851,6 +862,9 @@ func (m *Model) ensureSelectionNavigable() {
 }
 
 func (m *Model) recordKeyDebug(msg tea.KeyPressMsg, handled, moved bool) {
+	if !flameKeyDebugEnabled {
+		return
+	}
 	keyID := keyString(msg)
 	if keyID == "" {
 		keyID = fmt.Sprintf("code:%d", msg.Code)
@@ -1137,6 +1151,28 @@ func (m Model) frameIndexAt(x, y int) int {
 	return best
 }
 
+func (m Model) zoomLineageGeometry(fallbackLineWidth int) (lineWidth, gutter int, ok bool) {
+	if m.zoomPath == "" || m.width <= 0 {
+		return 0, 0, false
+	}
+	lineWidth = m.zoomLineWidth
+	if lineWidth <= 0 {
+		lineWidth = fallbackLineWidth
+	}
+	if lineWidth <= 0 {
+		lineWidth = m.width / 4
+	}
+	lineWidth = min(max(lineWidth, 3), max(3, m.width/3))
+	if lineWidth >= m.width-2 {
+		return 0, 0, false
+	}
+	gutter = lineWidth + 1
+	if m.width-gutter < minFlameWidth/2 {
+		return 0, 0, false
+	}
+	return lineWidth, gutter, true
+}
+
 func (m Model) withZoomLineage(frames []tuiFrame) []tuiFrame {
 	if len(frames) == 0 || m.snapshot == nil {
 		return frames
@@ -1146,16 +1182,16 @@ func (m Model) withZoomLineage(frames []tuiFrame) []tuiFrame {
 		return frames
 	}
 
-	lineWidth := m.zoomLineWidth
-	if lineWidth <= 0 {
-		lineWidth = frames[0].Width
+	fallbackLineWidth := 0
+	if len(frames) > 0 {
+		fallbackLineWidth = frames[0].Width
 	}
-	lineWidth = min(max(lineWidth, 3), max(3, m.width/3))
-	if lineWidth >= m.width-2 {
+	_, gutter, ok := m.zoomLineageGeometry(fallbackLineWidth)
+	if !ok {
 		return frames
 	}
-	gutter := lineWidth + 1
-	if m.width-gutter < minFlameWidth/2 {
+	lineageWidth := m.width - gutter
+	if lineageWidth < 1 {
 		return frames
 	}
 
@@ -1186,9 +1222,9 @@ func (m Model) withZoomLineage(frames []tuiFrame) []tuiFrame {
 		name := parts[depth]
 		out = append(out, tuiFrame{
 			Name:    name,
-			Col:     0,
+			Col:     gutter,
 			Row:     depth,
-			Width:   lineWidth,
+			Width:   lineageWidth,
 			Total:   total,
 			Percent: percent,
 			Fill:    terminalFrameColor(name),
diff --git a/internal/tui/flamegraph/model_test.go b/internal/tui/flamegraph/model_test.go
index bbd2005..59130ec 100644
--- a/internal/tui/flamegraph/model_test.go
+++ b/internal/tui/flamegraph/model_test.go
@@ -276,7 +276,7 @@ func TestMouseClickOutsideBarsDoesNotChangeSelectionOrZoom(t *testing.T) {
 	}
 }
 
-func TestZoomKeepsNarrowLineageRail(t *testing.T) {
+func TestZoomLineageSpansZoomViewportAndAlignsAtGutter(t *testing.T) {
 	m := newZoomModel()
 	targetPath := "root" + pathSeparator + "A"
 	targetIdx := mustFrameIndex(t, m.frames, targetPath)
@@ -289,14 +289,77 @@ func TestZoomKeepsNarrowLineageRail(t *testing.T) {
 
 	rootIdx := mustFrameIndex(t, m.frames, "root")
 	zoomIdx := mustFrameIndex(t, m.frames, targetPath)
-	if m.frames[rootIdx].Width != expectedRailWidth {
-		t.Fatalf("expected root lineage width %d, got %d", expectedRailWidth, m.frames[rootIdx].Width)
+	_, gutter, ok := m.zoomLineageGeometry(expectedRailWidth)
+	if !ok {
+		t.Fatalf("expected lineage geometry to be enabled for zoomed view")
+	}
+	expectedLineageWidth := m.width - gutter
+	if m.frames[rootIdx].Width != expectedLineageWidth {
+		t.Fatalf("expected root lineage width %d, got %d", expectedLineageWidth, m.frames[rootIdx].Width)
+	}
+	if m.frames[zoomIdx].Width != expectedLineageWidth {
+		t.Fatalf("expected zoom lineage width %d, got %d", expectedLineageWidth, m.frames[zoomIdx].Width)
+	}
+	if m.frames[rootIdx].Col != gutter || m.frames[zoomIdx].Col != gutter {
+		t.Fatalf("expected lineage rail at column %d, got root=%d zoom=%d", gutter, m.frames[rootIdx].Col, m.frames[zoomIdx].Col)
+	}
+}
+
+func TestZoomLineageKeepsAllFramesWithinViewportWidth(t *testing.T) {
+	m := newZoomModel()
+	m.selectedIdx = mustFrameIndex(t, m.frames, "root"+pathSeparator+"A")
+	m = pressFlameKey(t, m, tea.KeyPressMsg{Code: tea.KeyEnter})
+	m = settleFlameAnimation(t, m)
+
+	for _, frame := range m.frames {
+		if frame.Col+frame.Width > m.width {
+			t.Fatalf("frame exceeds viewport width %d: %+v", m.width, frame)
+		}
+	}
+}
+
+func TestZoomLineageAlignsWithZoomedSubtreeColumn(t *testing.T) {
+	m := newZoomModel()
+	rootPath := "root" + pathSeparator + "A"
+	childPath := rootPath + pathSeparator + "A1"
+	m.selectedIdx = mustFrameIndex(t, m.frames, rootPath)
+	m = pressFlameKey(t, m, tea.KeyPressMsg{Code: tea.KeyEnter})
+	m = settleFlameAnimation(t, m)
+
+	rootIdx := mustFrameIndex(t, m.frames, rootPath)
+	childIdx := mustFrameIndex(t, m.frames, childPath)
+	_, gutter, ok := m.zoomLineageGeometry(m.zoomLineWidth)
+	if !ok {
+		t.Fatalf("expected lineage geometry to be enabled")
+	}
+	if got := m.frames[rootIdx].Col; got != gutter {
+		t.Fatalf("expected zoom lineage root column %d, got %d", gutter, got)
 	}
-	if m.frames[zoomIdx].Width != expectedRailWidth {
-		t.Fatalf("expected zoom lineage width %d, got %d", expectedRailWidth, m.frames[zoomIdx].Width)
+	if got := m.frames[childIdx].Col; got != gutter {
+		t.Fatalf("expected first child column to align at %d, got %d", gutter, got)
 	}
-	if m.frames[rootIdx].Col != 0 || m.frames[zoomIdx].Col != 0 {
-		t.Fatalf("expected lineage rail at column 0, got root=%d zoom=%d", m.frames[rootIdx].Col, m.frames[zoomIdx].Col)
+}
+
+func TestZoomLineageParentsAreNeverNarrowerThanChildren(t *testing.T) {
+	m := newZoomModel()
+	rootPath := "root" + pathSeparator + "A"
+	m.selectedIdx = mustFrameIndex(t, m.frames, rootPath)
+	m = pressFlameKey(t, m, tea.KeyPressMsg{Code: tea.KeyEnter})
+	m = settleFlameAnimation(t, m)
+
+	for _, frame := range m.frames {
+		parentPath := parentFramePath(frame.Path)
+		if parentPath == "" {
+			continue
+		}
+		parentIdx := m.frameIndexByPath(parentPath)
+		if parentIdx < 0 {
+			continue
+		}
+		parent := m.frames[parentIdx]
+		if parent.Width < frame.Width {
+			t.Fatalf("expected parent %q width %d >= child %q width %d", parent.Path, parent.Width, frame.Path, frame.Width)
+		}
 	}
 }
 
@@ -587,32 +650,19 @@ func TestZoomInOnCurrentRootSetsStatusMessage(t *testing.T) {
 	}
 }
 
-func TestZoomTransitionAnimatesToNewLayout(t *testing.T) {
+func TestZoomTransitionAppliesNewLayoutImmediately(t *testing.T) {
 	m := newZoomModel()
 	pathA := "root" + pathSeparator + "A"
-	preWidth := m.frames[mustFrameIndex(t, m.frames, pathA)].Width
 
 	m.selectedIdx = mustFrameIndex(t, m.frames, pathA)
 	m = pressFlameKey(t, m, tea.KeyPressMsg{Code: tea.KeyEnter})
-	if !m.animating {
-		t.Fatalf("expected zoom-in to start animation")
+	if m.animating {
+		t.Fatalf("expected zoom-in layout update to apply immediately")
 	}
 	currentWidth := m.frames[mustFrameIndex(t, m.frames, pathA)].Width
 	targetWidth := m.targetFrames[mustFrameIndex(t, m.targetFrames, pathA)].Width
-	if currentWidth == targetWidth {
-		t.Fatalf("expected intermediate zoom frame width to differ from target (current=%d target=%d, pre=%d)", currentWidth, targetWidth, preWidth)
-	}
-
-	for i := 0; i < 180 && m.animating; i++ {
-		next, _ := m.Update(animTickMsg{})
-		m = next.(Model)
-	}
-	if m.animating {
-		t.Fatalf("expected zoom animation to settle within 180 ticks")
-	}
-	finalWidth := m.frames[mustFrameIndex(t, m.frames, pathA)].Width
-	if finalWidth != targetWidth {
-		t.Fatalf("expected final zoom width %d, got %d", targetWidth, finalWidth)
+	if currentWidth != targetWidth {
+		t.Fatalf("expected zoom width %d after immediate layout update, got %d", targetWidth, currentWidth)
 	}
 }
 
@@ -1067,6 +1117,14 @@ func mustFrameIndex(t *testing.T, frames []tuiFrame, path string) int {
 	return -1
 }
 
+func parentFramePath(path string) string {
+	lastSep := strings.LastIndex(path, pathSeparator)
+	if lastSep <= 0 {
+		return ""
+	}
+	return path[:lastSep]
+}
+
 func pressFlameKey(t *testing.T, m Model, keyMsg tea.KeyPressMsg) Model {
 	t.Helper()
 	next, _ := m.Update(keyMsg)