Generates UUIDv7 identifiers for Condukt.Session instances.

UUIDv7 (RFC 9562) embeds a millisecond Unix timestamp in the high bits, so identifiers are roughly time-ordered: useful for index locality in downstream stores that persist session telemetry, and for human inspection.

Callers that mint their own session ids (for example, to correlate a Condukt session with an external run record) can pass an :id option to Condukt.start_link/2 and Condukt.run/2 instead of generating one here.

Generation is delegated to Uniq.UUID.uuid7/0.