ApniKundli Astrology Web Application

I already own the domain for ApniKundli and now need the complete web application built. The flow is straightforward: a visitor enters नाम, जन्म तिथि, समय और place; completes payment through Razorpay; the system verifies the transaction in real-time and instantly generates a personalised Vedic Kundli PDF, emailing a copy to the user while storing the order in the database.

Core build requirements
• Vedic astrology calculation must rely on a proven, well-documented engine so that planetary positions, dashas and Vargas are accurate. Let me know exactly which library or SaaS you will integrate, along with licensing terms.
• Admin panel: only simple user management is required for now—view orders, resend emails, download PDFs, and manage basic site settings.
• Content management should support both Customizable templates and Dynamic content so I can refresh texts, banners and PDF layouts without touching code.
• Initial stack is your choice (PHP / Laravel, Node.js, Django, etc.) as long as it scales and keeps response time low; please outline your recommendation.
• Clean, well-commented source code to be handed over in full on final payment. All domain, hosting and API accounts (Razorpay, mail service, astrology engine) must be registered in my name.

Future-phase roadmap
I will soon add कुंडली मिलान, न्यूमेरोलॉजी, एस्ट्रोलॉजर कंसल्टेशन and Hast Rekha modules, so design the architecture to plug these in with minimal refactor.

What I need from you in the proposal
1. A detailed quotation broken into clear milestones (development, testing, deployment, warranty).
2. Realistic delivery timeline for each milestone.
3. The exact Kundli calculation engine you will use and why you trust it.
4. A link to a live demo or similar work you have already delivered.
5. Confirmation that the entire source code, build scripts and documentation will be transferred to me.
6. Assurance that all domains, hosting plans and API keys will remain under my ownership from day one.

Payment will be released only after I review and approve the above information, so please include everything up front. Looking forward to your complete proposal.