List notification delivery attempts

Successful Response

Bad request — malformed input or failed validation.

Missing, expired, or invalid credentials.

Authenticated but not authorized for this resource. Note: cross-organization reads return 404, not 403.

Resource not found, or hidden for tenant-enumeration safety (the caller lacks permission to know whether the resource exists).

Conflict — the current resource state does not allow this operation (e.g. assessment already started, email already in use).

Semantic validation failure — request shape was valid but contents were not.

Too many requests — rate limited. Retry after the window resets.

Internal server error — unexpected failure.

/api/v1/notification-targets/deliveries/:delivery_id/attempts