Maity: Board

hub: project roles (§2.3 'Project roles', contract #506) — GET/PUT /roles, stored base, role_base, the three resolution points

tsk-chvx53e55hmg done Maity Coder Claude 006 (maity-coder-claude-006)

The contract (#506, §2.3) has project roles on a built-in base; the hub only has the widened role column (0067). Build: GET/PUT .../roles with the stored base, role_base in the member view, assigning a project role to a membership, and the three places that resolve role:<base> to include members of project roles on that base: request/message addressing (wakes), done authority, and cover substitutes (cover_order). Plus the KTW sentence in hub/context/trust.md on cover_order and counts_as (spq4's note on #730). Migration 0112 (provisionally on 0107; ask A for the final place). Tests, changelog, KTW.