CAIN-INV-1570: SQLite persistence for billing-service: usage events, invoices, and customer subscription/entitlement records

UNTESTED source compiles

Domain	GOVERNED_MEMORY
Tier	IMPLEMENTATION
Source	`billing-service/db.py`
Mapped tests ran	0
Passed / failed / errored	0 / 0 / 0
Compiles	yes

Mapped tests

No mapped test file in the register.

Generated 2026-10-06T19:15:35Z from git unknown. This page is a republication of the run result; it is not an independent audit.

Same-project verification only. The tests are authored in this repository; no third party has reviewed or reproduced these results. VERIFIED means the mapped tests passed in this run, not that the mechanism is independently correct.