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>

text/typewriter.go

@@ -23,7 +23,7 @@ type TypewriterOptions struct {
 }
 
 type TypewriterResult struct {
-	Element *ui.Element
+	Element ui.Element
 	// Done is true in the frame the whole text shows.
 	Done bool
 }
@@ -45,7 +45,7 @@ func Typewriter(c *ui.Context, s string, o TypewriterOptions) TypewriterResult {
 	}
 	// S5 steps at 4–15 fps; fast typing shows more.
 	fps := max(4, min(cps, 15))
-	shell, base, st := pixel.Shell(c, func() *ui.Element {
+	shell, base, st := pixel.Shell(c, func() ui.Element {
 		e := ui.Box(c).Role(ui.RoleText).Label(s).Disabled(o.Disabled)
 		if !o.Disabled {
 			e.Focusable()