chore(v2): vendor dependencies for offline/China builds

go mod vendor pins onnxruntime_go v1.12.1, Gio and the rest into v2/vendor
so go run/build work without hitting proxy.golang.org (blocked/slow in
China). Verified: CGO_ENABLED=1 go build -mod=vendor ./internal/spike and
GOOS=windows go build -mod=vendor ./internal/ui both pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

v2/vendor/gioui.org/widget/bool.go

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package widget
+
+import (
+	"gioui.org/io/semantic"
+	"gioui.org/layout"
+)
+
+type Bool struct {
+	Value bool
+
+	clk Clickable
+}
+
+// Update the widget state and report whether Value was changed.
+func (b *Bool) Update(gtx layout.Context) bool {
+	changed := false
+	for b.clk.clicked(b, gtx) {
+		b.Value = !b.Value
+		changed = true
+	}
+	return changed
+}
+
+// Hovered reports whether pointer is over the element.
+func (b *Bool) Hovered() bool {
+	return b.clk.Hovered()
+}
+
+// Pressed reports whether pointer is pressing the element.
+func (b *Bool) Pressed() bool {
+	return b.clk.Pressed()
+}
+
+func (b *Bool) History() []Press {
+	return b.clk.History()
+}
+
+func (b *Bool) Layout(gtx layout.Context, w layout.Widget) layout.Dimensions {
+	b.Update(gtx)
+	dims := b.clk.layout(b, gtx, func(gtx layout.Context) layout.Dimensions {
+		semantic.SelectedOp(b.Value).Add(gtx.Ops)
+		semantic.EnabledOp(gtx.Enabled()).Add(gtx.Ops)
+		return w(gtx)
+	})
+	return dims
+}