Add modular billing credit ledger

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Add modular Razorpay billing, credit wallets, ledger reservations, and v2 memory workflow metering.
 - Add durable Temporal-backed v2 memory and scanner workflow APIs with job status, retry, cancel, and dead-letter endpoints.
 - Add modular LoCoMo and BEAM benchmark runners for the Python XMem API.
 - Add local XMem setup through `npx create-xmem@latest` and `npm run dev`.