## Summary
- notify customers by SMS with approve/deny links when a subuser
requests access
- notify subusers by SMS after approval or denial, including manual
grant changes
- support subuser password reset and authenticated password changes
- add read-only token previews followed by explicit POST confirmation
- store short-lived one-time purpose-bound action tokens only as SHA-256
digests
- serialize grant decisions transactionally to prevent conflicting
concurrent actions
- document the API contract in OpenAPI
## Security
- generic reset responses reduce account enumeration
- URL tokens are removed from browser history after frontend bootstrap
- approval previews never mutate state
- concurrent decisions lock the exact grant row
- SMS failures remain non-fatal and are returned as delivery status
Residual risk: existing subuser sessions cannot all be centrally
invalidated after password reset because there is no per-subuser session
index; they expire normally within the existing session lifetime.
## Verification
- backend Pest: 14 tests, 91 assertions
- PHP syntax checks passed
- focused PHPStan passed
- OpenAPI YAML parsed successfully
- `git diff --check` passed
Database-backed API integration tests were unavailable because the local
environment lacks the required database configuration.
## Paired delivery
Paired Frontend PR:
https://github.com/copenhagentruckwash/pleno-vue/pull/231
Both PRs are required before completion. The frontend PR contains the
responsive visual comparisons.
Co-authored-by: Jeppe Bundgaard <jb@truckwash.dk>
