Adiciona links acadêmicos ao MicrositeHeaderBlock e formatadores de campo

- Formatadores FieldFormatter para Lattes, ORCID e MathSciNet: geram
  link para o perfil na plataforma a partir do ID armazenado no campo
- MicrositeHeaderBlock: inclui lattes_id, orcid_id e mathscinet_id
- Template: exibe ícones SVG via site_tools_academic_icon() (extensão
  Twig do módulo site_tools) com links acessíveis para cada plataforma
- CSS: estilos para .msite-header-block__academic-links com animação
  de hover nos ícones

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

src/Plugin/Field/FieldFormatter/MathSciNetLinkFormatter.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Drupal\site_users\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Url;
+
+/**
+ * Formata o MathSciNet ID como link para o perfil de autor no MathSciNet.
+ *
+ * URL gerada: https://mathscinet.ams.org/mathscinet/author?AuthorID={id}
+ *
+ * @FieldFormatter(
+ *   id = "site_users_mathscinet_link",
+ *   label = @Translation("Link para o perfil MathSciNet"),
+ *   field_types = {"integer"}
+ * )
+ */
+#[FieldFormatter(
+  id: 'site_users_mathscinet_link',
+  label: new TranslatableMarkup('Link para o perfil MathSciNet'),
+  field_types: ['integer'],
+)]
+class MathSciNetLinkFormatter extends FormatterBase {
+
+  public static function isApplicable(FieldDefinitionInterface $field_definition): bool {
+    return $field_definition->getName() === 'field_user_mathscinetid';
+  }
+
+  public function viewElements(FieldItemListInterface $items, $langcode): array {
+    $elements = [];
+    foreach ($items as $delta => $item) {
+      $id = (string) $item->value;
+      $elements[$delta] = [
+        '#type' => 'link',
+        '#title' => $id,
+        '#url' => Url::fromUri('https://mathscinet.ams.org/mathscinet/author?AuthorID=' . $id),
+        '#attributes' => ['target' => '_blank', 'rel' => 'noopener noreferrer'],
+      ];
+    }
+    return $elements;
+  }
+
+}