feat(phase-4): Complete scheduling and automation system

- Add Celery worker with 5 scheduled tasks (Beat)
- Create ContentScheduler for optimal posting times
- Add calendar endpoints for scheduled posts management
- Implement Telegram notification service
- Add notification API with setup guide

Celery Beat Schedule:
- check_scheduled_posts: Every minute
- generate_daily_content: Daily at 6 AM
- sync_interactions: Every 15 minutes
- send_daily_summary: Daily at 9 PM
- cleanup_old_data: Weekly on Sundays

New endpoints:
- GET /api/calendar/posts/scheduled - List scheduled posts
- GET /api/calendar/posts/view - Calendar view
- GET /api/calendar/posts/slots - Available time slots
- POST /api/calendar/posts/{id}/schedule - Schedule post
- POST /api/calendar/posts/{id}/publish-now - Publish immediately
- GET /api/notifications/status - Check notification config
- POST /api/notifications/test - Send test notification
- GET /api/notifications/setup-guide - Configuration guide

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/main.py

@@ -11,7 +11,7 @@ from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 from fastapi.middleware.cors import CORSMiddleware
 
-from app.api.routes import posts, products, services, calendar, dashboard, interactions, auth, publish, generate
+from app.api.routes import posts, products, services, calendar, dashboard, interactions, auth, publish, generate, notifications
 from app.core.config import settings
 from app.core.database import engine
 from app.models import Base
@@ -64,6 +64,7 @@ app.include_router(calendar.router, prefix="/api/calendar", tags=["Calendar"])
 app.include_router(interactions.router, prefix="/api/interactions", tags=["Interactions"])
 app.include_router(publish.router, prefix="/api/publish", tags=["Publish"])
 app.include_router(generate.router, prefix="/api/generate", tags=["AI Generation"])
+app.include_router(notifications.router, prefix="/api/notifications", tags=["Notifications"])
 
 
 @app.get("/api/health")