perf: DynamicFields reads each post type's fields once per check (review M-12 b)

reason() and note() run per key and type of a body check; they now share one
offered() result per post type, so the default storage callback loads each
pod once instead of per call.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/Integrations/Divi/Pages/DynamicFields.php

@@ -38,6 +38,9 @@ class DynamicFields
     /** @var Closure(string): ?string */
     private Closure $podStorage;
 
+    /** @var array<string, array{0: list<array<string, string>>, 1: list<array<string, string>>}> offered() by type. */
+    private array $known = [];
+
     /** @param (Closure(string): ?string)|null $podStorage Post type → Pods storage ("meta", "table"), null: none. */
     public function __construct(private ContentSchema $schema, ?Closure $podStorage = null)
     {
@@ -72,10 +75,21 @@ class DynamicFields
         return [$fields, $omitted];
     }
 
+    /**
+     * offered() once per post type for reason()/note() – they run per key and type of a check, and the default
+     * storage callback loads the pod each time (review M-12 b).
+     *
+     * @return array{0: list<array<string, string>>, 1: list<array<string, string>>}
+     */
+    private function known(string $postType): array
+    {
+        return $this->known[$postType] ??= $this->offered($postType);
+    }
+
     /** Why {{field:$key}} would not show as text for $postType; null when it does. */
     public function reason(string $postType, string $key): ?string
     {
-        [$fields, $omitted] = $this->offered($postType);
+        [$fields, $omitted] = $this->known($postType);
         foreach ($fields as $field) {
             if ($field['key'] === $key) {
                 return null;
@@ -93,7 +107,7 @@ class DynamicFields
     /** What to know about an offered field of $postType ($key) that shows other text than expected; else null. */
     public function note(string $postType, string $key): ?string
     {
-        [$fields] = $this->offered($postType);
+        [$fields] = $this->known($postType);
         foreach ($fields as $field) {
             if ($field['key'] === $key && $field['type'] === 'choice') {
                 return 'Auswahlfeld – Divi zeigt den gespeicherten Wert, nicht die Beschriftung';