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>

input/stepper.go

@@ -19,7 +19,7 @@ type StepperOptions struct {
 }
 
 type StepperResult struct {
-	Element *ui.Element
+	Element ui.Element
 	Changed bool
 }
 
@@ -35,7 +35,7 @@ func Stepper(c *ui.Context, text string, value *int, o StepperOptions) StepperRe
 	w := max(pixel.Measure(strconv.Itoa(o.Min)), pixel.Measure(strconv.Itoa(o.Max))) + 8
 	e := ui.Row(c).Gap(k.D(2)).AlignItems(ui.Center).Children(func() {
 		set(*value - step*held(c, k, tinyLeft, o.Disabled))
-		shell, base, st := pixel.Shell(c, func() *ui.Element {
+		shell, base, st := pixel.Shell(c, func() ui.Element {
 			return ui.Box(c).Focusable().Role(ui.RoleStepper).Label(text).Description(strconv.Itoa(*value)).Disabled(o.Disabled)
 		})
 		if !o.Disabled {