OrganizationOption as lightweight key-value store for idempotency caching

Sentry's OrganizationOption (sentry.models.options.organization_option) provides org-scoped JSON key-value storage with built-in caching and no migration needed. Keys are limited to 64 characters. For idempotency keys (which can be arbitrarily long), hash them: stripe-projects:idem:<sha256[:16]> fits in ~40 chars. Lookup: OrganizationOption.objects.get_value(org, key, default=None). Write: OrganizationOption.objects.set_value(org, key, dict_value). Values persist as long as the org exists. This pattern avoids new models, Redis TTL concerns, and migrations. ProjectOption provides the same for project-scoped storage.