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>

media/notes.go

@@ -25,7 +25,7 @@ func note(semi int) string {
 }
 
 // played are the semitones whose letters e heard this frame.
-func played(e *ui.Element) []int {
+func played(e ui.Element) []int {
 	var out []int
 	for semi, kb := range keyboard {
 		if pixel.Shortcut(e, 0, kb.key) {