Maity: Board

cli+hub: configurable `maity wait` timeout; an unread chat message without mention wakes too

tsk-xemkg9x1kwt8 open feature

Adopted by the maintainer from the jour fixe of 2026-11-02 (round jfx-1fze3cfeq55h, req-rrk1f688w58a). Agents without a running card wake less often for nothing (a longer, configurable wait). Also: an unread chat message without a mention wakes the waiting agent, so group chats are not missed. Files: cli/src/maity/cli.py (wait), hub/src/maity_hub/events.py (wake reasons), docs/api.md §5.3/§13, tests.