[interface-documentation] Validation API reference

[ivosh]

Description

OpenAPI reference for the validation surfaces. Carved out of the SM: AdES child #222, which narrows to the AdES formatting controller now that this umbrella owns the validation and trust-configuration controllers.

Estimate (agent execution - review/verify/supervise): 0.25 md
Human baseline: 0.5 md

Children

• Register validation and trust-configuration controllers; regenerate specs #224 - Register validation and trust-configuration controllers; regenerate specs - 0.25 / 0.5 md

Total: 0.25 / 0.5 md committed

Dependencies

• [interfaces] Signature validation contract merged (the controller exists)