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>

input/multiselect.go

@@ -18,7 +18,7 @@ type MultiSelectOptions struct {
 }
 
 type MultiSelectResult struct {
-	Element *ui.Element
+	Element ui.Element
 	Changed bool
 }
 
@@ -30,7 +30,7 @@ type popup struct{ open, held bool }
 // MultiSelect checks many options in a popup; tags show them.
 func MultiSelect(c *ui.Context, text string, chosen *[]string, options []string, o MultiSelectOptions) MultiSelectResult {
 	k := pixel.K(c)
-	shell, base, st := pixel.Shell(c, func() *ui.Element {
+	shell, base, st := pixel.Shell(c, func() ui.Element {
 		return ui.ButtonBase(c).Role(ui.RolePopUpButton).Label(text).Description(strings.Join(*chosen, ", ")).Disabled(o.Disabled)
 	})
 	pop := ui.Local(base, multiKey{}, func() popup { return popup{} })
@@ -58,15 +58,15 @@ func MultiSelect(c *ui.Context, text string, chosen *[]string, options []string,
 	})
 	res := MultiSelectResult{Element: shell}
 	pop.held = false
-	ui.PopoverBase(c, base, open, func(panel *ui.Element) {
+	ui.PopoverBase(c, base, open, func(panel ui.Element) {
 		menu(c, panel, func() {
 			col := ui.Column(c).Gap(k.D(1)).FocusGroup(ui.Vertical)
 			col.Children(func() {
 				for i, opt := range options {
 					on := slices.Contains(*chosen, opt)
-					item, cb, cst := pixel.Shell(c, func() *ui.Element { return ui.CheckboxBase(c, &on).Label(opt) })
+					item, cb, cst := pixel.Shell(c, func() ui.Element { return ui.CheckboxBase(c, &on).Label(opt) })
 					if i == 0 {
-						cb.AutoFocus()
+						pixel.AutoFocus(c, cb)
 					}
 					// Focused, not FocusWithin: MyGo links parents after frames.
 					pop.held = pop.held || cb.Focused()