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>

datetime/yearview.go

@@ -15,7 +15,7 @@ type YearViewOptions struct{}
 const miniW, miniH, monthW, monthH = 10, 7, 7*miniW + 4, 6*miniH + pixel.LineHeight + 2
 
 // YearView sets a year's twelve months small; today is marked.
-func YearView(c *ui.Context, year int, o YearViewOptions) *ui.Element {
+func YearView(c *ui.Context, year int, o YearViewOptions) ui.Element {
 	k := pixel.K(c)
 	now := today(c, k)
 	return ui.Box(c).Size(k.D(4*monthW), k.D(3*monthH)).Role(ui.RoleImage).Label(strconv.Itoa(year)).Draw(func(p *ui.Painter, r ui.Rect) {