feat: Divi tools write library entries; global ones with dry run, confirm and backup (E2, F2)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Integrations/Divi/Library/LibraryAccess.php

@@ -53,7 +53,7 @@ class LibraryAccess
      * names no library entry (the caller goes on with PostGuard). With the library hidden (ruling
      * P9) or without the library right at all (ruling P12), an entry is refused exactly like an ID
      * that does not exist, so its type and existence stay unknown; only a user with the library
-     * right who lacks edit_post on the entry gets forbidden (like pages).
+     * right who lacks edit_post on the entry gets forbidden (like pages). $forWrite adds canEdit().
      */
     public function item(mixed $postId, bool $forWrite): WP_Post|WP_Error|null
     {
@@ -67,7 +67,7 @@ class LibraryAccess
             return PostGuard::notFound((int) $post->ID);
         }
 
-        return $this->canRead($post) ?? $post;
+        return ($forWrite ? $this->canEdit($post) : $this->canRead($post)) ?? $post;
     }
 
     /** Listing the library: edit_posts and the Divi role option divi_library. */
@@ -93,6 +93,47 @@ class LibraryAccess
             : Errors::forbidden(sprintf('Keine Berechtigung, Bibliothekseintrag %d zu bearbeiten.', (int) $item->ID));
     }
 
+    /**
+     * Changing one entry: canRead(), the role option save_library, the Tools-tab gate and a live
+     * entry; a global entry additionally needs edit_global_library (E3 – Divi's builder route
+     * does not check edit_post on the entry, F9; LIT MCP does).
+     */
+    public function canEdit(WP_Post $item): ?WP_Error
+    {
+        $refusal = $this->canRead($item) ?? $this->roles->refusal('save_library') ?? $this->writableGate();
+        if ($refusal !== null) {
+            return $refusal;
+        }
+
+        if ((string) $item->post_status !== 'publish') {
+            return Errors::invalidInput(
+                sprintf(
+                    'Bibliothekseintrag %d ist nicht aktiv (Status „%s“); nichts wurde gespeichert.',
+                    (int) $item->ID,
+                    (string) $item->post_status
+                ),
+                ['post_id' => 'nur aktive Bibliothekseinträge'],
+                'Den Eintrag zuerst in der Divi-Bibliothek wiederherstellen.'
+            );
+        }
+
+        return $this->isGlobal($item) ? $this->roles->refusal('edit_global_library') : null;
+    }
+
+    /** Refusal while the Tools tab keeps this connection from writing to the library. */
+    public function writableGate(): ?WP_Error
+    {
+        if ($this->writable === null || ($this->writable)()) {
+            return null;
+        }
+
+        return Errors::forbidden(
+            'Schreiben in die Divi-Bibliothek ist für diese Verbindung abgeschaltet (Gruppe „Divi-Bibliothek“ auf '
+                . '„nur lesen“ oder deaktiviert).',
+            'Einen Administrator fragen: Einstellungen → LIT MCP → Tools.'
+        );
+    }
+
     public function isGlobal(WP_Post $item): bool
     {
         return $this->store->isGlobal((int) $item->ID);