refactor: type declarations via Rector

rector.php gets the typeDeclarations set: return types (void, array,
unions) where the code proves them, typed closures and arrow functions,
typed properties from constructors and assignments in the DTOs.

Skipped: rules that infer scalar or array parameter types from call
sites or docblocks, and the removal of casts the docblocks call
redundant. Values from the database, form input and the import feeds
arrive as strings and would throw instead of being converted (e.g. the
(int) cast of the newsletter list ids stays).

Checked locally: cache warmup, frontend crawl (~1,900 URLs), the
backchannel APIs and the newsletter form validation behave as before.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Classes/Domain/Model/Page.php

@@ -45,7 +45,7 @@ class Page extends AbstractEntity
     /**
      * @param bool $hidden
      */
-    public function setHidden($hidden)
+    public function setHidden($hidden): void
     {
         $this->hidden = $hidden;
     }
@@ -61,7 +61,7 @@ class Page extends AbstractEntity
     /**
      * @param string $title
      */
-    public function setTitle($title)
+    public function setTitle($title): void
     {
         $this->title = $title;
     }
@@ -77,7 +77,7 @@ class Page extends AbstractEntity
     /**
      * @param string $seoTitle
      */
-    public function setSeoTitle($seoTitle)
+    public function setSeoTitle($seoTitle): void
     {
         $this->seoTitle = $seoTitle;
     }
@@ -93,7 +93,7 @@ class Page extends AbstractEntity
     /**
      * @param string $description
      */
-    public function setDescription($description)
+    public function setDescription($description): void
     {
         $this->description = $description;
     }