fix: populate sidebar context for pages using Page with Sidebar template, use block_template_part for footer (v1.0.6)

- ContextBuilder now calls getSidebarData() when page template slug is
  'page-sidebar', fixing empty sidebar on pages with that template
- Added block_template_part() Twig function to TwigService for FSE
  Template Editor compatibility
- Changed footer rendering from include to block_template_part() so
  footer edits in the Template Editor take effect

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

inc/Twig/TwigService.php

@@ -136,6 +136,13 @@ class TwigService
         $this->twig->addFunction(new TwigFunction('number_format_i18n', function (float $number, int $decimals = 0): string {
             return number_format_i18n($number, $decimals);
         }));
+
+        // Block template parts (allows FSE Template Editor changes to take effect).
+        $this->twig->addFunction(new TwigFunction('block_template_part', function (string $part): string {
+            ob_start();
+            block_template_part($part);
+            return ob_get_clean();
+        }, ['is_safe' => ['html']]));
     }
 
     private function registerWordPressGlobals(): void