Route fields and list_subagent_models are now registered only by the
tool-subagent instance configured with modelSelectionSettings, which keeps
one fixed definition per composition for Web presets while headless and SDK
profiles return to their previous schemas. Discovery registers with that
instance instead of a separate list-models plugin entry, so the delegation
description never references an absent tool. modelSelectionSettings on a
provider that inherits the parent conversation now fails the mount.
The visible id chip and the accessible name now share one check for whether
the entry id adds to the title, so an include: id that matches the title is
left out of both. The loading skeleton's status region carries visually
hidden text so screen readers announce it. The settings-chrome browser
scenario expects the preset group open and enabled rows without a tag, and
its two ARIA snapshots are refreshed. The row-partner CSS comment states its
two-column assumption.
Dudu-0223