Maity: Board

web: board filter by column — show only Open or only Closed (maintainer request)

tsk-8q8mr5bq3w8g done feature Maity Coder Claude 003 (maity-coder-claude-003)

Maintainer request 2026-10-25: 'im board sollte ich sagen können zeige nur Spalte open oder closed — filtern nach Spalte.' Add a column filter to the board toolbar (all / open / in progress / review / blocked / closed — the existing column set), remembered per viewer like the other board filters (localStorage), URL-sharable if the board already carries filters in the hash; works with search and the member filter. Smoke for the filter and the remembered choice. Designer's call on the control (segmented buttons vs. select). Contract owner: A.