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>

agent/agentcard.go

@@ -24,7 +24,7 @@ type AgentCardOptions struct {
 const cardW, cardH = 136, 48
 
 // AgentCard is a party card: class, level, context as HP.
-func AgentCard(c *ui.Context, a Agent, o AgentCardOptions) *ui.Element {
+func AgentCard(c *ui.Context, a Agent, o AgentCardOptions) ui.Element {
 	k := pixel.K(c)
 	if a.Name == "" || a.Class == "" || a.Level < 1 || a.Window < 1 || a.Used < 0 || a.Used > a.Window {
 		panic(fmt.Sprintf("agent: AgentCard %q, %q, LV %d, %d of %d tokens", a.Name, a.Class, a.Level, a.Used, a.Window))