Fix PHPStan error and remove type hint for compatibility

- Fix class name case: Visualizer_PRO → Visualizer_Pro in Block.php (2 occurrences)
- Remove WP_Post type hint from _getChartArray for PHP compatibility

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: vytisbulkevicius

classes/Visualizer/Gutenberg/Block.php

@@ -469,7 +469,7 @@ public function get_visualizer_data( $post ) {
 		}
 
 		if ( Visualizer_Module::is_pro() ) {
-			$permissions = get_post_meta( $post_id, Visualizer_PRO::CF_PERMISSIONS, true );
+			$permissions = get_post_meta( $post_id, Visualizer_Pro::CF_PERMISSIONS, true );
 
 			if ( empty( $permissions ) ) {
 				$permissions = array( 'permissions' => array(
@@ -664,7 +664,7 @@ public function update_chart_data( $data ) {
 			}
 
 			if ( Visualizer_Module::is_pro() ) {
-				update_post_meta( $data['id'], Visualizer_PRO::CF_PERMISSIONS, $data['visualizer-permissions'] );
+				update_post_meta( $data['id'], Visualizer_Pro::CF_PERMISSIONS, $data['visualizer-permissions'] );
 			}
 
 			if ( $data['visualizer-chart-url'] ) {

classes/Visualizer/Module/Chart.php

@@ -379,7 +379,7 @@ public function getCharts() {
 	 *
 	 * @return array The array of chart data.
 	 */
-	private function _getChartArray( WP_Post $chart = null ) {
+	private function _getChartArray( $chart = null ) {
 		if ( is_null( $chart ) ) {
 			$chart = $this->_chart;
 		}