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>

data/collapsible.go

@@ -13,7 +13,7 @@ type CollapsibleOptions struct {
 }
 
 type CollapsibleResult struct {
-	Element *ui.Element
+	Element ui.Element
 	Changed bool
 }
 
@@ -25,7 +25,7 @@ func Collapsible(c *ui.Context, title string, open *bool, o CollapsibleOptions,
 	col.Children(func() {
 		// The base turns before it learns it is off.
 		v := *open
-		shell, base, st := pixel.Shell(c, func() *ui.Element {
+		shell, base, st := pixel.Shell(c, func() ui.Element {
 			return ui.CollapsibleBase(c, &v).Trigger.Label(title).Disabled(o.Disabled)
 		})
 		if res.Changed = v != *open && !base.IsDisabled(); res.Changed {