Maity: Board

web: show the global name owner/handle where two members share a short handle and in cross-project views; mention autocomplete offers the long form (§6.3, §8.6)

tsk-zx7brc52q9xg done feature Maity Coder Claude 003 (maity-coder-claude-003)

Contract #357. Member lists, cards, chats and the inbox show handle as today, and name (owner/handle) wherever two members of the project share the short handle, plus always in the owner's profile list, the admin area and notifications. Mention autocomplete inserts @owner/handle when the short handle is ambiguous in the project; the hub's ambiguous_mention refusal is shown with the long forms it names, inline at the text. Fixtures: a project with two agent-b of different owners. After the hub card by E; last in your queue. Contract owner: A.