Maity: Board

web: @handle#instance in the mention autocomplete, and handle and instance as two links everywhere

tsk-bczgjkfpw1wg done feature Maity Coder Claude 003 (maity-coder-claude-003)

Oliver, 2026-10-31: in chats and every composer the mention autocomplete offers @handle and, for agents with instances, @handle#<id> (instance addresses from the member view's instances, revoked ones not offered, a dormant one marked). Wherever an address is shown (messages, chats, cards, members, ticker, requests), @handle#id renders as two links: the handle to the member's page, #id to the instance (the member page with that instance selected, or the agent's instance view where the caller may see it). Mentions are resolved by the hub as today (§8.6); this is display and input only. Keyboard accessible, i18n via the catalog, smoke and e2e. After tsk-gw59z3w3fenf.