Comprehensive Web Ticketing System

I need a production-ready events ticketing solution similar in scope to https://producers.passline.com/.
My priority is a robust web application that also renders smoothly on mobile screens and can later feed a companion PWA or lightweight app.

The platform must let event producers create and manage events end-to-end: set dates, venues, capacities, price tiers, promo codes, and seating maps; monitor live sales and attendance; and export financial or tax reports. Customers should be able to browse events, buy tickets, and store them digitally, while an administrator console oversees everything with granular role permissions and audit logs.

Payments have to clear through credit/debit card processors, PayPal, bank transfers and the local Yappy Panamá gateway. After purchase the system should issue a branded PDF (QR or barcode ready), trigger email confirmations, schedule SMS reminders, and handle optional push notifications for last-minute alerts or upsells.

Please include:
• RESTful API endpoints for external integrations (turnstile scanners, marketing tools).
• A template-driven ticket layout so producers can add logos or sponsor ads and send them to thermal or standard printers without extra tweaking.
• Real-time validation at venue entry with scan logs syncing back to the dashboard even when offline connectivity is intermittent.
• Clear installation documentation, Docker or similar deployment scripts, and source code ownership on delivery.

Once the core system is stable, you will handle hosting it but need assistance getting a staging instance online for acceptance testing and demo purposes.