fix(dev): load runtime metadata without frontend build artifacts

web/embed.go

@@ -5,7 +5,9 @@
 package web
 
 import (
+	"bytes"
 	"embed"
+	"fmt"
 	"io/fs"
 )
 
@@ -19,3 +21,19 @@ func Dist() fs.FS {
 	}
 	return sub
 }
+
+// BuildVersion 与页面入口使用同一构建标识，生产产物缺失时明确失败。
+func BuildVersion() (string, error) {
+	html, err := fs.ReadFile(Dist(), "index.html")
+	if err != nil {
+		return "", err
+	}
+	marker := []byte(`<meta name="rawmark-version" content="`)
+	if start := bytes.Index(html, marker); start >= 0 {
+		rest := html[start+len(marker):]
+		if end := bytes.IndexByte(rest, '"'); end > 0 {
+			return string(rest[:end]), nil
+		}
+	}
+	return "", fmt.Errorf("缺少构建版本")
+}