Function set_seat_state 

pub fn set_seat_state(
    db: &Db,
    org: &str,
    project: &str,
    label: &str,
    state: SeatState,
    reopen: bool,
) -> Result<bool>

Move the row at (org, project, label) to state, keeping every other field.

Closed is authoritative. Unless reopen states that an opening door asked for the seat, a write leaves a closed row closed: the task a close tore down can still drain a queued /resume or translate a Result, and one of those writes landing would reopen a project the user shut. Returns whether a row existed; a row that is not there is not created, because the state describes an occupant the row names.