web: adding an agent under Agents and joining straight away shows no reports_to field

tsk-nbadjbr9zpg7 open

Oliver (owner), chat seq 82495, 2026-11-06: in a project, under Agents, he adds an agent and goes straight on to the join. The form there has no field to pick reports_to.

Check first, and say in the PR which of these it is:

Is it the web only? The join/creation call already accepts reports_to (docs/api.md §6.2, and the join creation in §3), but the form doesn't offer it.
Or does the contract or hub not accept reports_to on that path? Then it's a contract card first; tell me before you build.

Wanted: in this flow, a reports_to select with the same options and rules as on the member's settings (members of the project; a cross-owner choice files the consent request as §6.2 says). It's optional, and empty stays allowed.
Checks: e2e for the add+join flow with and without reports_to; layout 1280x900 and 390x844, light and dark; LANGUAGE=en_US. Do it after tsk-4e17b8xnp8eq. Run the overlap check with kg22 and eyq5.