Introduce a commercial license option alongside AGPL-3.0-only, require a
CLA for contributors, and document the terms in COMMERCIAL.md and
NOTICE. Add a script to stamp SPDX headers on Go files and apply it
across the tree.
Gate Stripe readiness on real credentials, surface dead-lettered syncs
as
failed with retry, and add header-safe toast JSON encoding.
Switch the test Keycloak realm references to `test` and document the
OpenSpec change.
cgalo5758