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/app/egl_android.go

@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+//go:build !noopengl
+
+package app
+
+/*
+#include <android/native_window_jni.h>
+#include <EGL/egl.h>
+*/
+import "C"
+
+import (
+	"unsafe"
+
+	"gioui.org/internal/egl"
+)
+
+type androidContext struct {
+	win     *window
+	eglSurf egl.NativeWindowType
+	*egl.Context
+}
+
+func init() {
+	newAndroidGLESContext = func(w *window) (context, error) {
+		ctx, err := egl.NewContext(nil)
+		if err != nil {
+			return nil, err
+		}
+		return &androidContext{win: w, Context: ctx}, nil
+	}
+}
+
+func (c *androidContext) Release() {
+	if c.Context != nil {
+		c.Context.Release()
+		c.Context = nil
+	}
+}
+
+func (c *androidContext) Refresh() error {
+	c.Context.ReleaseSurface()
+	if err := c.win.setVisual(c.Context.VisualID()); err != nil {
+		return err
+	}
+	win, _, _ := c.win.nativeWindow()
+	c.eglSurf = egl.NativeWindowType(unsafe.Pointer(win))
+	return nil
+}
+
+func (c *androidContext) Lock() error {
+	// The Android emulator creates a broken surface if it is not
+	// created on the same thread as the context is made current.
+	if c.eglSurf != nil {
+		if err := c.Context.CreateSurface(c.eglSurf); err != nil {
+			return err
+		}
+		c.eglSurf = nil
+	}
+	return c.Context.MakeCurrent()
+}
+
+func (c *androidContext) Unlock() {
+	c.Context.ReleaseCurrent()
+}