feat: Adiciona field type social_link para redes sociais do usuário

Implementa o field type 'social_link' com seletor de rede e URL de
perfil, composto por:

- SocialLinkItem: field type com colunas 'network' (varchar 64) e
  'url' (varchar 2048), cardinalidade ilimitada
- SocialLinkWidget: widget com select de rede e input de URL
- SocialLinkFormatter: formatter que renderiza links com classe CSS
  por rede (social-link--{network}), target _blank e rel noopener
- config/optional: field.storage e field.field para user
- config/translations/pt-br: tradução do label e description
- hook_install e update_10002: configura form/view displays
- UserInfoBlock: expõe social_links via getSocialLinks()
- Template: adiciona seção de redes sociais e remove referências
  obsoletas a category e dept_code
- translations/site_users.pt-br.po: strings do novo field type

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

src/Plugin/Field/FieldFormatter/SocialLinkFormatter.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Drupal\site_users\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Url;
+use Drupal\site_users\Plugin\Field\FieldType\SocialLinkItem;
+
+/**
+ * Plugin implementation of the 'social_link_formatter' formatter.
+ *
+ * @FieldFormatter(
+ *   id = "social_link_formatter",
+ *   label = @Translation("Social link"),
+ *   field_types = {
+ *     "social_link"
+ *   }
+ * )
+ */
+class SocialLinkFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode): array {
+    $elements = [];
+    $networks = SocialLinkItem::getNetworks();
+
+    foreach ($items as $delta => $item) {
+      if ($item->isEmpty()) {
+        continue;
+      }
+
+      $network_label = $networks[$item->network] ?? $item->network;
+
+      $elements[$delta] = [
+        '#type' => 'link',
+        '#title' => $network_label,
+        '#url' => Url::fromUri($item->url),
+        '#attributes' => [
+          'class' => ['social-link', 'social-link--' . $item->network],
+          'target' => '_blank',
+          'rel' => 'noopener noreferrer',
+        ],
+      ];
+    }
+
+    return $elements;
+  }
+
+}