Interiolane SaaS -Multi-Tenant Platform Development

Interiolane SaaS — Product Development Requirements (PDR)Document type: Implementation-ready product development requirements derived from the Interiolane master SRS.Primary objective: Build a multi-tenant SaaS platform for modular furniture, interior design, construction, manufacturing, procurement, real estate, finance, customer portals, AI workflows, and controlled communications.Required production stack: Next.js and React on Vercel; Supabase PostgreSQL and Supabase Auth/Storage where selected; Razorpay for payments; Hostinger for domain and DNS management.Commercial invariant: Interiolane is Quote-First for commercial preparation, but inventory is Invoice-First for authoritative availability validation and commitment. A quotation may construct invoice lines and show indicative information, but it shall not reserve, deduct, or commit inventory.1. Build mandateBuild a production-quality, multi-tenant application with strict tenant isolation, role and scope authorization, customer-safe projections, immutable financial and inventory records, approval workflows, audit evidence, mobile-ready APIs, and modular architecture. The implementation shall preserve version history for quotations, designs, documents, invoices, inventory policies, payments, permissions, and production-relevant records.