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>

shop/quantity.go

@@ -18,7 +18,7 @@ type QuantityOptions struct {
 }
 
 type QuantityResult struct {
-	Element *ui.Element
+	Element ui.Element
 	Changed bool
 }
 
@@ -29,7 +29,7 @@ func Quantity(c *ui.Context, text string, value *int, o QuantityOptions) Quantit
 	if lo < 0 || hi < lo || *value < lo || *value > hi {
 		panic(fmt.Sprintf("shop: Quantity %d outside %d to %d", *value, lo, hi))
 	}
-	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).Disabled(o.Disabled)
 	})
 	old, nw := *value, pixel.Measure(strconv.Itoa(hi))+6