feat: LinkedIn editorial, accesos agencia estables y deshacer en historial

Integra estrategias LinkedIn en calendarios (backlog publicado vs pendiente), unifica roles/cookies de vista agencia y permite deshacer cambios de brandbook dejando constancia en el historial.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/pipeline-publish-worker.ts

@@ -215,6 +215,28 @@ export async function processDuePipelinePublishes(opts?: {
     let igPermalink: string | null = null;
     let fbPermalink: string | null = null;
 
+    // LinkedIn-only: stub hasta API key (no pasa por Meta)
+    if (
+      channels.includes('linkedin') &&
+      !channels.includes('instagram') &&
+      !channels.includes('facebook')
+    ) {
+      const li = await publishPipelineItem(item);
+      await patchItem(base, headers, item.id, {
+        publish_status: li.ok ? 'published' : 'failed',
+        publish_error: li.error || null,
+        published_at: li.ok ? new Date().toISOString() : null,
+        publish_attempts: (item.publish_attempts || 0) + 1,
+      });
+      results.push({
+        id: item.id,
+        title: item.title,
+        ok: Boolean(li.ok),
+        detail: li.ok ? 'linkedin' : li.error || 'linkedin_failed',
+      });
+      continue;
+    }
+
     if (channels.includes('instagram') && !igMediaId && channelDue('instagram')) {
       const ig = await publishPipelineItem(item, { skipFb: true });
       if (ig.sanitizedCaption && ig.sanitizedCaption !== (item.caption || '')) {