feat: Integrate social media scheduler startup and shutdown events into the main application.

app.py

@@ -9,10 +9,18 @@ import dotenv
 dotenv.load_dotenv()
 
 from github_workflow_app.app import app as github_app
-from social_media_publishers.app import app as social_app
+from social_media_publishers.app import app as social_app, start_scheduler, shutdown_scheduler
 
 app = FastAPI()
 
+@app.on_event("startup")
+async def startup_event():
+    await start_scheduler()
+
+@app.on_event("shutdown")
+async def shutdown_event():
+    await shutdown_scheduler()
+
 app.mount("/github_workflow", github_app)
 app.mount("/social", social_app)