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/material/progressbar.go

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package material
+
+import (
+	"image"
+	"image/color"
+
+	"gioui.org/internal/f32color"
+	"gioui.org/layout"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/unit"
+)
+
+type ProgressBarStyle struct {
+	Color      color.NRGBA
+	Height     unit.Dp
+	Radius     unit.Dp
+	TrackColor color.NRGBA
+	Progress   float32
+}
+
+func ProgressBar(th *Theme, progress float32) ProgressBarStyle {
+	return ProgressBarStyle{
+		Progress:   progress,
+		Height:     unit.Dp(4),
+		Radius:     unit.Dp(2),
+		Color:      th.Palette.ContrastBg,
+		TrackColor: f32color.MulAlpha(th.Palette.Fg, 0x88),
+	}
+}
+
+func (p ProgressBarStyle) Layout(gtx layout.Context) layout.Dimensions {
+	shader := func(width int, color color.NRGBA) layout.Dimensions {
+		d := image.Point{X: width, Y: gtx.Dp(p.Height)}
+		rr := gtx.Dp(p.Radius)
+
+		defer clip.UniformRRect(image.Rectangle{Max: image.Pt(width, d.Y)}, rr).Push(gtx.Ops).Pop()
+		paint.ColorOp{Color: color}.Add(gtx.Ops)
+		paint.PaintOp{}.Add(gtx.Ops)
+
+		return layout.Dimensions{Size: d}
+	}
+
+	progressBarWidth := gtx.Constraints.Max.X
+	return layout.Stack{Alignment: layout.W}.Layout(gtx,
+		layout.Stacked(func(gtx layout.Context) layout.Dimensions {
+			return shader(progressBarWidth, p.TrackColor)
+		}),
+		layout.Stacked(func(gtx layout.Context) layout.Dimensions {
+			fillWidth := int(float32(progressBarWidth) * clamp1(p.Progress))
+			fillColor := p.Color
+			if !gtx.Enabled() {
+				fillColor = f32color.Disabled(fillColor)
+			}
+			if fillWidth < int(p.Radius*2) {
+				fillWidth = int(p.Radius * 2)
+			}
+			return shader(fillWidth, fillColor)
+		}),
+	)
+}
+
+// clamp1 limits v to range [0..1].
+func clamp1(v float32) float32 {
+	if v >= 1 {
+		return 1
+	} else if v <= 0 {
+		return 0
+	} else {
+		return v
+	}
+}