v4.1: Complete Settings page — role, team, API keys, dates, admin badge, danger zone

Replace Stripe with Razorpay: subscriptions, webhooks, checkout modal, INR pricing

v3: All missing features — auth callback, settings, PDF export, email (Resend), JWT auth, /api/history, SaulLM integration, extension icons, Supabase 0.10 breaking changes, Stripe v22