## Summary - Adds two new workspace audit events for the AARRR funnel tracked in ClickHouse - **Workspace Created**: emitted in `signUpOnNewWorkspace` after the transaction commits, capturing every new workspace creation - **Payment Received**: emitted in `processInvoicePaid` on every Stripe `invoice.paid` webhook, with `stripeInvoiceId`, `amountPaid`, and `billingReason` properties. First payment per workspace can be derived at query time via `min(timestamp)` grouped by `workspaceId` ## Test plan - [x] Verify `Workspace Created` event appears in ClickHouse after signing up on a new workspace - [x] Verify `Payment Received` event appears in ClickHouse after a Stripe `invoice.paid` webhook fires - [x] Confirm no event is emitted if the billing customer cannot be resolved from `stripeCustomerId` - [x] Run existing `SignInUpService` unit tests pass with the new `AuditService` mock Made with [Cursor](https://cursor.com) --------- Co-authored-by: Cursor <cursoragent@cursor.com>