Update Facebook API call to correctly schedule posts

Modifies the `published` parameter in the FacebookService from 'false' to '0' for scheduled posts. Includes a new n8n workflow JSON file for asset management.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/Ob3gzfQ

server/services/facebook.ts

@@ -121,7 +121,7 @@ export class FacebookService {
     const params = new URLSearchParams({
       access_token: page.accessToken!,
       message: post.content,
-      published: 'false',
+      published: '0',
       scheduled_publish_time: scheduledTimestamp.toString(),
     });
 
@@ -147,7 +147,7 @@ export class FacebookService {
       access_token: page.accessToken!,
       message: post.content,
       url: photoUrl,
-      published: 'false',
+      published: '0',
       scheduled_publish_time: scheduledTimestamp.toString(),
     });