Add isolated Razorpay Live ₹1 pilot rail

[Phloraxx]

Summary

Adds a separate Razorpay Live Mode pilot without weakening or reusing the Test rail.

• separate razorpay_live_orders and razorpay_live_events collections;
• separate /api/razorpay/live/* config/order/verify/refresh/webhook routes;
• strict rzp_live_ configuration validation;
• independent Live API Key Secret and webhook secret;
• exact ₹1 server-side pilot cap;
• signed callback verification, provider fetch and monotonic webhook state;
• separate Docker volume/deployment template;
• no raw webhook payload or customer payment-detail retention.

Verification

• complete Go suite passed;
• go vet ./... passed;
• complete race-detector suite passed;
• explicit tests prove non-₹1 amounts never call Razorpay;
• Test Mode rail remains separate and unchanged.