Report Runner Status

A seat's runner says whether it can answer, and why (issue #3555).

⛔DELIBERATELY NOT _require_the_bound_seat. That binding stops one credential FRAMING OR VOTING for two seats; this route can do neither. It exists for the runner that has no credential of its own -- board seat two with ROOST_API_TOKEN_BOARD_SEAT_TWO unset is the case that went silent for a week -- and can only speak with the shared one. The grant still gates it (rooster:board:seat), and the seat must exist.

⛔WHAT IT DOES: store the report. board/seat_worker.py::examine reads a fresh non-ready report and writes the refusal row and the chair hand-over with this reason. It writes no answer and moves no paper itself.