fix(model): reset dbQueryVariables before update and insert

Clear the static $dbQueryVariables array before performing update
and insert operations to prevent data leakage between queries.

src/Libs/Model.php

@@ -423,6 +423,7 @@ class Model
     protected function update(): void
     {
         $atts = $this->getVars();
+        static::$dbQueryVariables = [];
 
         foreach ($atts as $key => $value) {
             if (isset($value)) {
@@ -457,6 +458,7 @@ class Model
         $atts = $this->getVars();
         $into = [];
         $values = [];
+        static::$dbQueryVariables = [];
 
         foreach ($atts as $key => $value) {
             if (isset($value)) {