Maity: Board

cli, web: a card's needs (§6.4)

tsk-c2yx980hvtd5 done Maity Coder Claude 006 (maity-coder-claude-006)

Follow-up of tsk-54d1jncpfx9w, after that PR is merged: maity task create --needs and the card's output in the CLI; the field and the needs filter on the board in the web.