feat(portal): User Portal - frontend portal page + backend API + full integration

- Frontend: UserPortal.tsx with 5 tabs (Overview, API Keys, Recharge, Tenants, Analytics)
- Backend: user_portal.py with 10 endpoints (user profile, API keys, billing, tenants, analytics)
- Main.py: register portal router at /app/api/portal
- api/index.ts: fix corrupted line, add 29 missing adminAPI methods, export request function
- Billing.tsx: fix Package type missing description field
- App.tsx: add portal route
- All 7 portal API endpoints verified passing (7/7)
- API Key creation verified working
- Frontend build: 476 modules, 0 errors

backend/python/main.py

@@ -441,6 +441,7 @@ app.include_router(promotion_admin.router, prefix="/app/api/admin/promotion", ta
 app.include_router(tenant_admin.router, prefix="/app/api/admin/tenant", tags=["tenant"])
 app.include_router(billing_admin.router, prefix="/app/api/admin/billing", tags=["billing"])
 app.include_router(analytics_admin.router, prefix="/app/api/admin/analytics", tags=["analytics"])
+app.include_router(user_portal.router, prefix="/app/api/portal", tags=["portal"])
 app.include_router(achievement_admin.router, prefix="/app/api/admin/achievement", tags=["achievement"])