bug fix:修复可能的panic状态；增加更多功能

internal/scanutil/value_clone.go

@@ -0,0 +1,12 @@
+package scanutil
+
+// CloneScannedValue copies driver-scanned values that may be reused by driver.
+// []byte is deep-copied; other types are returned as-is.
+func CloneScannedValue(val interface{}) interface{} {
+	if b, ok := val.([]byte); ok {
+		copied := make([]byte, len(b))
+		copy(copied, b)
+		return copied
+	}
+	return val
+}