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/gpu/api.go

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package gpu
+
+import "gioui.org/gpu/internal/driver"
+
+// An API carries the necessary GPU API specific resources to create a Device.
+// There is an API type for each supported GPU API such as OpenGL and Direct3D.
+type API = driver.API
+
+// A RenderTarget denotes the destination framebuffer for a frame.
+type RenderTarget = driver.RenderTarget
+
+// OpenGLRenderTarget is a render target suitable for the OpenGL backend.
+type OpenGLRenderTarget = driver.OpenGLRenderTarget
+
+// Direct3D11RenderTarget is a render target suitable for the Direct3D 11 backend.
+type Direct3D11RenderTarget = driver.Direct3D11RenderTarget
+
+// MetalRenderTarget is a render target suitable for the Metal backend.
+type MetalRenderTarget = driver.MetalRenderTarget
+
+// VulkanRenderTarget is a render target suitable for the Vulkan backend.
+type VulkanRenderTarget = driver.VulkanRenderTarget
+
+// OpenGL denotes the OpenGL or OpenGL ES API.
+type OpenGL = driver.OpenGL
+
+// Direct3D11 denotes the Direct3D API.
+type Direct3D11 = driver.Direct3D11
+
+// Metal denotes the Apple Metal API.
+type Metal = driver.Metal
+
+// Vulkan denotes the Vulkan API.
+type Vulkan = driver.Vulkan
+
+// ErrDeviceLost is returned from GPU operations when the underlying GPU device
+// is lost and should be recreated.
+var ErrDeviceLost = driver.ErrDeviceLost