a5aecf26fa
Non-dispatch gateways no longer open per-board kanban DBs for notifier polling. Mirrors the existing dispatcher gate (config kanban.dispatch_in_gateway, default True; env override HERMES_KANBAN_DISPATCH_IN_GATEWAY) so multi-gateway setups collapse to a single process holding kanban.db file descriptors. Salvaged from PR #31964 by @steveonjava; tests and docs trimmed during salvage.