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>

code/profilerbars.go

@@ -25,7 +25,7 @@ type ProfilerBarsOptions struct {
 var depths = []pixel.Slot{pixel.Accent, pixel.Info, pixel.Good, pixel.Warn, pixel.Magic}
 
 // ProfilerBars stacks spans under their parents, each bar its time.
-func ProfilerBars(c *ui.Context, text string, root Span, o ProfilerBarsOptions) *ui.Element {
+func ProfilerBars(c *ui.Context, text string, root Span, o ProfilerBarsOptions) ui.Element {
 	k := pixel.K(c)
 	w := pixel.Or("ProfilerBars Width", o.Width, 240)
 	if root.Length <= 0 {