Add Facebook publishing functionality to schedule posts

Integrate Facebook Graph API for publishing scheduled posts, including media. Update storage to handle post-media relationships and add new schema types.

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

shared/schema.ts

@@ -254,3 +254,5 @@ export type InsertCloudinaryConfig = z.infer<typeof insertCloudinaryConfigSchema
 
 export type OpenrouterConfig = typeof openrouterConfig.$inferSelect;
 export type InsertOpenrouterConfig = z.infer<typeof insertOpenrouterConfigSchema>;
+
+export type PostMedia = typeof postMedia.$inferSelect;