Cancel a parent invite

Upgrades a player's session to an active one, creating challenges where the requested permissions need guardian consent. Identify the session by `sessionId`, by `kuid`, or by both — both together associate that user with an existing session. Passing neither is a bad request. Use `options` to tune age assurance for any challenge this call mints, and `materialChange` to name the exact legal documents to present for consent. Setting `materialChange.acceptanceDeadline` makes the upgrade deadline-bound: the guardian is emailed an approve-request link and must accept by that timestamp. Any future UTC timestamp is honoured exactly as supplied — there is no minimum window and no rounding — so a deadline minutes away stays minutes away. Omit it to present the documents with no deadline. Set `priorChallengeId` to re-consent when documents change. The new challenge supersedes a pending or in-progress one and adds to its documents (additive only), and any earlier link resolves to the latest. `requestedPermissions` may be empty. On a session that still has data notices awaiting guardian acceptance, an empty array requests that re-consent on its own: with a guardian already on file the response carries a `CHALLENGE_MATERIAL_CHANGE` scoped to exactly the outstanding notices, and with no guardian on file it carries a full `CHALLENGE_PARENTAL_CONSENT` that collects the guardian and presents the product's whole picture. On a session with nothing outstanding an empty array returns the session unchanged and no challenge. Pair it with `priorChallengeId` to supersede a challenge that is already pending rather than adding another alongside it. `priorChallengeId` only takes effect when the call mints a challenge; on a request that mints none, such as one asking only for player-managed permissions, it is still validated but the prior challenge is left as it is. A one-time password on a returned challenge expires. Call `/challenge/generate-otp` when you are ready to display it, and regenerate it periodically until the challenge is in progress.