chore(tui): delete dead braille code, hoist sparkWidth, stop resize flash

1. Delete braille.go + braille_test.go — dead code, only referenced
   by its own test. Can be re-added when latency charts are built.

2. Hoist duplicate `const sparkWidth = 40` (update.go + view_detail.go)
   to package-level `detailSparkWidth`. Click-index resolution and
   rendering now share one constant.

3. Remove tea.ClearScreen on every resize — caused full-screen flash
   during continuous resizes. ctrl+l manual clear kept.

internal/tui/braille.go

@@ -1,103 +0,0 @@
-package tui
-
-// braillePlane is a subpixel canvas where each terminal cell maps to a 2×4
-// dot grid, rendered via Unicode braille (U+2800..U+28FF).
-type braillePlane struct {
-	wCells, hCells int
-	wDots, hDots   int
-	dots           []bool
-}
-
-func newBraillePlane(wCells, hCells int) *braillePlane {
-	wd, hd := wCells*2, hCells*4
-	return &braillePlane{
-		wCells: wCells, hCells: hCells,
-		wDots: wd, hDots: hd,
-		dots: make([]bool, wd*hd),
-	}
-}
-
-func (p *braillePlane) set(dx, dy int) {
-	if dx < 0 || dy < 0 || dx >= p.wDots || dy >= p.hDots {
-		return
-	}
-	p.dots[dy*p.wDots+dx] = true
-}
-
-// line draws a Bresenham line between two dot coordinates.
-func (p *braillePlane) line(x0, y0, x1, y1 int) {
-	dx := intAbs(x1 - x0)
-	sx := 1
-	if x0 >= x1 {
-		sx = -1
-	}
-	dy := -intAbs(y1 - y0)
-	sy := 1
-	if y0 >= y1 {
-		sy = -1
-	}
-	err := dx + dy
-	for {
-		p.set(x0, y0)
-		if x0 == x1 && y0 == y1 {
-			return
-		}
-		e2 := 2 * err
-		if e2 >= dy {
-			err += dy
-			x0 += sx
-		}
-		if e2 <= dx {
-			err += dx
-			y0 += sy
-		}
-	}
-}
-
-// fillBelow fills all dots below the topmost lit dot in each column,
-// producing an area-chart effect.
-func (p *braillePlane) fillBelow() {
-	for x := 0; x < p.wDots; x++ {
-		topY := -1
-		for y := 0; y < p.hDots; y++ {
-			if p.dots[y*p.wDots+x] {
-				topY = y
-				break
-			}
-		}
-		if topY >= 0 {
-			for y := topY + 1; y < p.hDots; y++ {
-				p.dots[y*p.wDots+x] = true
-			}
-		}
-	}
-}
-
-// cellMask builds the U+2800-relative bitmask for one terminal cell.
-func (p *braillePlane) cellMask(cx, cy int) byte {
-	type bit struct {
-		dx, dy int
-		m      byte
-	}
-	bits := [...]bit{
-		{0, 0, 0x01}, {0, 1, 0x02}, {0, 2, 0x04},
-		{1, 0, 0x08}, {1, 1, 0x10}, {1, 2, 0x20},
-		{0, 3, 0x40}, {1, 3, 0x80},
-	}
-	var mask byte
-	for _, b := range bits {
-		dx := cx*2 + b.dx
-		dy := cy*4 + b.dy
-		if dx >= 0 && dx < p.wDots && dy >= 0 && dy < p.hDots && p.dots[dy*p.wDots+dx] {
-			mask |= b.m
-		}
-	}
-	return mask
-}
-
-func intAbs(n int) int {
-	if n < 0 {
-		return -n
-	}
-	return n
-}

internal/tui/braille_test.go

@@ -1,64 +0,0 @@
-package tui
-
-import "testing"
-
-func TestBraillePlane_Set(t *testing.T) {
-	p := newBraillePlane(2, 1)
-	if p.wDots != 4 || p.hDots != 4 {
-		t.Fatalf("expected 4x4 dots, got %dx%d", p.wDots, p.hDots)
-	}
-	p.set(0, 0)
-	if !p.dots[0] {
-		t.Error("dot at (0,0) should be set")
-	}
-	p.set(-1, 0) // out of bounds, should not panic
-	p.set(0, 99) // out of bounds, should not panic
-}
-
-func TestBraillePlane_CellMask(t *testing.T) {
-	p := newBraillePlane(1, 1)
-	// Set bottom-left dot
-	p.set(0, 3)
-	mask := p.cellMask(0, 0)
-	if mask != 0x40 {
-		t.Errorf("bottom-left dot should be 0x40, got 0x%02x", mask)
-	}
-	// Set all dots
-	for y := 0; y < 4; y++ {
-		for x := 0; x < 2; x++ {
-			p.set(x, y)
-		}
-	}
-	mask = p.cellMask(0, 0)
-	if mask != 0xFF {
-		t.Errorf("all dots should be 0xFF, got 0x%02x", mask)
-	}
-}
-
-func TestBraillePlane_Line(t *testing.T) {
-	p := newBraillePlane(3, 1)
-	p.line(0, 2, 5, 2) // horizontal line
-	for x := 0; x <= 5; x++ {
-		if !p.dots[2*p.wDots+x] {
-			t.Errorf("dot at (%d, 2) should be set", x)
-		}
-	}
-}
-
-func TestBraillePlane_FillBelow(t *testing.T) {
-	p := newBraillePlane(1, 1)
-	p.set(0, 1) // set dot at row 1
-	p.fillBelow()
-	if !p.dots[1*p.wDots+0] {
-		t.Error("original dot should still be set")
-	}
-	if !p.dots[2*p.wDots+0] {
-		t.Error("row 2 should be filled")
-	}
-	if !p.dots[3*p.wDots+0] {
-		t.Error("row 3 should be filled")
-	}
-	if p.dots[0*p.wDots+0] {
-		t.Error("row 0 above the dot should not be filled")
-	}
-}

internal/tui/tui.go

@@ -80,6 +80,8 @@ const (
 	chromeFooter = 2 // footer: "\n" prefix + text line
 	chromeTable  = 3 // renderTable "\n" prefix + top border + header + bottom border (lipgloss collapses two into three rendered lines)
 	chromeBase   = chromePadV + chromeHeader + chromeGaps + chromeFooter + chromeTable
+
+	detailSparkWidth = 40
 )
 
 type sessionState int

internal/tui/update.go

@@ -162,7 +162,7 @@ func (m *Model) handleResize(msg tea.WindowSizeMsg) (tea.Model, tea.Cmd) {
 	m.historyViewport.Height = msg.Height - 10
 	m.slaViewport.Width = msg.Width - chromePadH
 	m.slaViewport.Height = msg.Height - 16
-	return m, tea.ClearScreen
+	return m, nil
 }
 
 func (m *Model) handleTick(t time.Time) (tea.Model, tea.Cmd) {
@@ -392,16 +392,14 @@ func (m *Model) handleSparklineClick(msg tea.MouseMsg) (tea.Model, tea.Cmd) {
 	site := m.sites[m.cursor]
 	hist, _ := m.engine.GetHistory(site.ID)
 
-	const sparkWidth = 40
-
 	if zi := m.zones.Get("spark-latency"); zi != nil && !zi.IsZero() && zi.InBounds(msg) {
 		x, _ := zi.Pos(msg)
-		m.sparkTooltipIdx = resolveSparklineIndex(x, sparkWidth, len(hist.Latencies))
+		m.sparkTooltipIdx = resolveSparklineIndex(x, detailSparkWidth, len(hist.Latencies))
 		return m, nil
 	}
 	if zi := m.zones.Get("spark-heartbeat"); zi != nil && !zi.IsZero() && zi.InBounds(msg) {
 		x, _ := zi.Pos(msg)
-		m.sparkTooltipIdx = resolveSparklineIndex(x, sparkWidth, len(hist.Statuses))
+		m.sparkTooltipIdx = resolveSparklineIndex(x, detailSparkWidth, len(hist.Statuses))
 		return m, nil
 	}
 

internal/tui/view_detail.go

@@ -207,9 +207,8 @@ func (m Model) viewDetailPanel() string {
 	}
 
 	b.WriteString(m.divider() + "\n")
-	const sparkWidth = 40
 	if site.Type == "push" {
-		b.WriteString("  " + m.zones.Mark("spark-heartbeat", m.heartbeatSparkline(hist.Statuses, sparkWidth, "")))
+		b.WriteString("  " + m.zones.Mark("spark-heartbeat", m.heartbeatSparkline(hist.Statuses, detailSparkWidth, "")))
 		if len(hist.Statuses) > 0 {
 			up := 0
 			for _, s := range hist.Statuses {
@@ -222,7 +221,7 @@ func (m Model) viewDetailPanel() string {
 				up, len(hist.Statuses))
 		}
 	} else {
-		b.WriteString("  " + m.zones.Mark("spark-latency", m.latencySparkline(hist.Latencies, hist.Statuses, sparkWidth, "")))
+		b.WriteString("  " + m.zones.Mark("spark-latency", m.latencySparkline(hist.Latencies, hist.Statuses, detailSparkWidth, "")))
 		var minL, maxL, total time.Duration
 		count := 0
 		for i, l := range hist.Latencies {
@@ -249,7 +248,7 @@ func (m Model) viewDetailPanel() string {
 	}
 
 	if m.sparkTooltipIdx >= 0 {
-		b.WriteString("\n" + m.renderSparkTooltip(site, hist, sparkWidth))
+		b.WriteString("\n" + m.renderSparkTooltip(site, hist, detailSparkWidth))
 	}
 
 	b.WriteString("\n")