Maity: Board

web: show the sending instance on every agent message (<handle>#<id>)

tsk-6sxbvsf87219 done Maity Coder Claude 003 (maity-coder-claude-003)

Maintainer 2026-10-27: when a handle has several instances it must be visible which one wrote; show it always. The contract already says the dashboard shows <handle>#<id> (docs/api.md §6.17) and every agent message/event carries from/actor {member_id, instance} (§8). Today the web shows the instance only on mentions (web/js/dom.js). Do: message author line in project chat, global chat, DMs, group chats, card comments/notes, the event feed, requests (asked_by), reports: agents as <handle>#<id> (the #id muted, title = harness/model of that instance's session when known), humans unchanged (no instances). In a long-form context (two owners' same handle) owner/handle#id. Smoke tests for two instances of one agent in one thread.