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/icon.go

@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package widget
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+
+	"gioui.org/internal/f32color"
+	"gioui.org/layout"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/unit"
+
+	"golang.org/x/exp/shiny/iconvg"
+)
+
+type Icon struct {
+	src []byte
+	// Cached values.
+	op       paint.ImageOp
+	imgSize  int
+	imgColor color.NRGBA
+}
+
+const defaultIconSize = unit.Dp(24)
+
+// NewIcon returns a new Icon from IconVG data.
+func NewIcon(data []byte) (*Icon, error) {
+	_, err := iconvg.DecodeMetadata(data)
+	if err != nil {
+		return nil, err
+	}
+	return &Icon{src: data}, nil
+}
+
+// Layout displays the icon with its size set to the X minimum constraint.
+func (ic *Icon) Layout(gtx layout.Context, color color.NRGBA) layout.Dimensions {
+	sz := gtx.Constraints.Min.X
+	if sz == 0 {
+		sz = gtx.Dp(defaultIconSize)
+	}
+	size := gtx.Constraints.Constrain(image.Pt(sz, sz))
+	defer clip.Rect{Max: size}.Push(gtx.Ops).Pop()
+
+	ico := ic.image(size.X, color)
+	ico.Add(gtx.Ops)
+	paint.PaintOp{}.Add(gtx.Ops)
+	return layout.Dimensions{
+		Size: ico.Size(),
+	}
+}
+
+func (ic *Icon) image(sz int, color color.NRGBA) paint.ImageOp {
+	if sz == ic.imgSize && color == ic.imgColor {
+		return ic.op
+	}
+	m, _ := iconvg.DecodeMetadata(ic.src)
+	dx, dy := m.ViewBox.AspectRatio()
+	img := image.NewRGBA(image.Rectangle{Max: image.Point{X: sz, Y: int(float32(sz) * dy / dx)}})
+	var ico iconvg.Rasterizer
+	ico.SetDstImage(img, img.Bounds(), draw.Src)
+	m.Palette[0] = f32color.NRGBAToLinearRGBA(color)
+	iconvg.Decode(&ico, ic.src, &iconvg.DecodeOptions{
+		Palette: &m.Palette,
+	})
+	ic.op = paint.NewImageOp(img)
+	ic.imgSize = sz
+	ic.imgColor = color
+	return ic.op
+}