Upgrade MyGo to v0.5.5

Elements are now pass-scoped value handles: tests that read bounds
after a frame bind a ui.Handle. pixel tells frames apart by the build
pass's root, since the Tester clock no longer moves on its own.

Fix the regressions the upgrade brought:
- Clipboard reads in input handlers go through c.Services().
- MyGo notes an overlay's opener after building it, so AutoFocus
  inside lost it; pixel.AutoFocus focuses through a Handle, and
  archtest bans the raw call. Dialogs hand the focus back again.
- Elements around a press stay hovered: Tooltip tells a press-given
  focus by focus arriving under the pointer.
- The web host moves the Tester clock with real time, at most 500 ms
  a call, and gives components the real clock.

The gallery's source index also accepts CRLF checkouts.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

gallery/boot.go

@@ -20,7 +20,7 @@ func (a *App) boot(c *ui.Context) {
 		shown = 16
 	}
 	start := shown == 16 && (k.Reduce() || step%12 < 8)
-	shell, base, _ := pixel.Shell(c, func() *ui.Element { return ui.ButtonBase(c).Label("Press start") })
+	shell, base, _ := pixel.Shell(c, func() ui.Element { return ui.ButtonBase(c).Label("Press start") })
 	shell.Fill().Draw(func(p *ui.Painter, r ui.Rect) {
 		g := k.Canvas(p, r)
 		w := pixel.Measure(logo) * 4
@@ -34,7 +34,7 @@ func (a *App) boot(c *ui.Context) {
 		hint := "Enter · Space · Click     回车 · 空格 · 点击"
 		g.Text((g.W-pixel.Measure(hint))/2, g.H-28, hint, pixel.Faint, 1)
 	})
-	base.AutoFocus()
+	pixel.AutoFocus(c, base)
 	if base.Clicked() || c.Shortcut(0, ui.KeyEnter) || c.Shortcut(0, ui.KeySpace) {
 		slog.Debug("8bit: gallery start")
 		a.started = true