feat(templates): add archive-header and post-grid components

- Add ArchiveHeader component (schema, renderer, formbuilder)
- Add PostGrid component (schema, renderer, formbuilder)
- Unify archive templates (home, archive, category, tag,
  author, date, search)
- Add page visibility system with VisibilityDefaults
- Register components in AdminDashboardRenderer
- Fix boolean conversion in functions-addon.php
- All 172 unit tests passed

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Infrastructure/Services/MigratePageVisibilityService.php

@@ -20,7 +20,7 @@ final class MigratePageVisibilityService
     ) {}
 
     /**
-     * Ejecuta la migración para todos los componentes
+     * Ejecuta la migracion para todos los componentes
      *
      * @return array{created: int, skipped: int}
      */
@@ -37,10 +37,10 @@ final class MigratePageVisibilityService
                 continue;
             }
 
-            // Usar constante compartida (DRY)
+            // Usar defaults especificos por componente si existen
             $this->visibilityRepository->createDefaultVisibility(
                 $componentName,
-                VisibilityDefaults::DEFAULT_VISIBILITY
+                VisibilityDefaults::getForComponent($componentName)
             );
             $created++;
         }