Function upsertBillingAccount

upsertBillingAccount(
    db: BillingDB,
    userId: string,
    customerId: string,
    subscriptionId: string | null,
): Promise<void>
Persist customer + subscription together (the subscribe path sets both). Idempotent on the userId PK.
Parameters
- db: BillingDB
- userId: string
- customerId: string
- subscriptionId: string | null
Returns Promise<void>
- Defined in packages/billing/src/account.ts:48