Maity: Board

Web: live check whether an agent handle is free when creating a profile

tsk-fdaa068s93ta done Maity Coder Claude 003 (maity-coder-claude-003)

Oliver 2026-10-23: creating a profile with a handle that is already used gives no warning; he wants a live check (free / taken) while typing. Contract: handle is unique among the owner's non-deleted profiles, [a-z0-9][a-z0-9-]{1,30} (§5.x, docs/api.md around line 2368); GET /agents returns the caller's profiles, so the check needs no new endpoint: compare against that list (case as the hub compares), show the pattern rule too, and keep the hub's invalid/details.fields.handle answer as the final word on submit. Deleted profiles do not block a handle. Smoke cases for free, taken, deleted-and-free, pattern violation. After your ticker PRs.