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/font/font.go

@@ -0,0 +1,126 @@
+/*
+Package font provides type describing font faces attributes.
+*/
+package font
+
+import (
+	"github.com/go-text/typesetting/font"
+)
+
+// A FontFace is a Font and a matching Face.
+type FontFace struct {
+	Font Font
+	Face Face
+}
+
+// Style is the font style.
+type Style int
+
+// Weight is a font weight, in CSS units subtracted 400 so the zero value
+// is normal text weight.
+type Weight int
+
+// Font specify a particular typeface variant, style and weight.
+type Font struct {
+	// Typeface specifies the name(s) of the the font faces to try. See [Typeface]
+	// for details.
+	Typeface Typeface
+	// Style specifies the kind of text style.
+	Style Style
+	// Weight is the text weight.
+	Weight Weight
+}
+
+// Face is an opaque handle to a typeface. The concrete implementation depends
+// upon the kind of font and shaper in use.
+type Face interface {
+	Face() *font.Face
+}
+
+// Typeface identifies a list of font families to attempt to use for displaying
+// a string. The syntax is a comma-delimited list of family names. In order to
+// allow for the remote possibility of needing to express a font family name
+// containing a comma, name entries may be quoted using either single or double
+// quotes. Within quotes, a literal quotation mark can be expressed by escaping
+// it with `\`. A literal backslash may be expressed by escaping it with another
+// `\`.
+//
+// Here's an example Typeface:
+//
+//	Times New Roman, Georgia, serif
+//
+// This is equivalent to the above:
+//
+//	"Times New Roman", 'Georgia', serif
+//
+// Here are some valid uses of escape sequences:
+//
+//	"Contains a literal \" doublequote", 'Literal \' Singlequote', "\\ Literal backslash", '\\ another'
+//
+// This syntax has the happy side effect that most CSS "font-family" rules are
+// valid Typefaces (without the trailing semicolon).
+//
+// Generic CSS font families are supported, and are automatically expanded to lists
+// of known font families with a matching style. The supported generic families are:
+//
+//   - fantasy
+//   - math
+//   - emoji
+//   - serif
+//   - sans-serif
+//   - cursive
+//   - monospace
+type Typeface string
+
+const (
+	Regular Style = iota
+	Italic
+)
+
+const (
+	Thin       Weight = -300
+	ExtraLight Weight = -200
+	Light      Weight = -100
+	Normal     Weight = 0
+	Medium     Weight = 100
+	SemiBold   Weight = 200
+	Bold       Weight = 300
+	ExtraBold  Weight = 400
+	Black      Weight = 500
+)
+
+func (s Style) String() string {
+	switch s {
+	case Regular:
+		return "Regular"
+	case Italic:
+		return "Italic"
+	default:
+		panic("invalid Style")
+	}
+}
+
+func (w Weight) String() string {
+	switch w {
+	case Thin:
+		return "Thin"
+	case ExtraLight:
+		return "ExtraLight"
+	case Light:
+		return "Light"
+	case Normal:
+		return "Normal"
+	case Medium:
+		return "Medium"
+	case SemiBold:
+		return "SemiBold"
+	case Bold:
+		return "Bold"
+	case ExtraBold:
+		return "ExtraBold"
+	case Black:
+		return "Black"
+	default:
+		panic("invalid Weight")
+	}
+}