feat: add category assignment translation keys

Add marketplace.fields.categories, marketplace.actions.assign_categories,
and marketplace.category_modal section with all modal UI strings.

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

resources/lang/pl.php

@@ -43,15 +43,28 @@ return [
             'channel' => 'Kanal',
             'product' => 'Produkt orderPRO',
             'updated_at' => 'Ostatnia zmiana',
+            'categories' => 'Kategorie',
             'actions' => 'Akcje',
         ],
         'actions' => [
             'open_offers' => 'Pokaz oferty',
             'back_to_marketplace' => 'Wroc do Marketplace',
+            'assign_categories' => 'Przypisz kategorie',
         ],
         'flash' => [
             'integration_not_found' => 'Nie znaleziono aktywnej integracji.',
         ],
+        'category_modal' => [
+            'title' => 'Przypisz kategorie',
+            'loading' => 'Ladowanie kategorii...',
+            'no_categories' => 'Brak dostepnych kategorii.',
+            'save' => 'Zapisz',
+            'cancel' => 'Anuluj',
+            'saving' => 'Zapisuje...',
+            'saved' => 'Kategorie zapisane.',
+            'error_save' => 'Blad zapisu.',
+            'error_network' => 'Blad sieci.',
+        ],
     ],
     'auth' => [
         'login' => [