D17 — API versioning: URL-versioned, v1 is the current default (RESOLVED)
Architecture decision record, relocated verbatim from the retired single-file
docs/tenancy/decision log. Status, thematic clusters, and how to record a new ADR: the decision log index.
The REST API is URL-versioned under /api/v1/… (central routes/api.php + tenant
routes/tenant.php). v1 is the current/default version, recorded in config/api.php
(current_version, supported_versions). Each version is registered explicitly per route
file so adding v2 never moves v1's routes. No unversioned fallback — clients pin a version
(best practice for a fintech API). Route names are namespaced: api.v1.*, tenant.api.v1.*.