chore: import clean Agent Desk snapshot (1/7)

cmd/testdata/seedlang/language.go

@@ -0,0 +1,25 @@
+package seedlang
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Language string
+
+const (
+	Chinese Language = "zh"
+	English Language = "en"
+)
+
+func Parse(raw string) (Language, error) {
+	normalized := strings.ToLower(strings.TrimSpace(raw))
+	switch normalized {
+	case "", "zh", "zh-cn", "chinese":
+		return Chinese, nil
+	case "en", "en-us", "english":
+		return English, nil
+	default:
+		return "", fmt.Errorf("unsupported testdata language %q, supported: zh, en", raw)
+	}
+}