Add SNS Marketing Campaign feature

- Add cash_cc_balance to User model (withdrawable CC)
- Create SnsShareSubmission model for SNS share verification
- Add marketing campaign settings to SystemSettings
- Add reward_type to ReferralReward model
- Create /api/sns-share endpoints for submission and verification
- Add referral signup reward logic (10CC on signup)
- Create /sns-share user page for SNS sharing
- Create /admin/sns-shares management page
- Add marketing settings UI to admin settings page
- Add SNS Shares menu to admin sidebar

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/app/main.py

@@ -9,7 +9,7 @@ import asyncio
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
 from apscheduler.triggers.cron import CronTrigger
 from .database import engine, Base, SessionLocal
-from .api import cars, auth, inquiries, hero_banners, carmodoo, translations, cc, settings, vehicle_requests, dealer, vehicle_share, withdrawal, referral, notification, dashboard, push, exchange_rate, verification, visitor
+from .api import cars, auth, inquiries, hero_banners, carmodoo, translations, cc, settings, vehicle_requests, dealer, vehicle_share, withdrawal, referral, notification, dashboard, push, exchange_rate, verification, visitor, sns_share
 from .config import get_settings
 from .services.exchange_rate_service import update_exchange_rates
 from .services.visitor_service import aggregate_daily_stats, cleanup_old_visitor_logs
@@ -201,6 +201,7 @@ app.include_router(push.router, prefix="/api")
 app.include_router(exchange_rate.router)
 app.include_router(verification.router, prefix="/api")
 app.include_router(visitor.router, prefix="/api")
+app.include_router(sns_share.router, prefix="/api")
 
 
 @app.get("/")