Master added this scenario while this branch was open, so its golden froze
the composer seat's "Select model" fallback. The scaffold's route-only
adapter (added here for fixture-less scenarios) makes the seat resolve the
model those scenarios actually route to, which is what the other eight
goldens on this branch already show. Only the two seat lines move.
`resolveModel` validated the profile's reasoning level against the exact
model and threw when it did not fit. That call builds the model catalog,
and the catalog build catches per PROVIDER — so one mis-set field took the
whole provider out of every picker behind a single error row, hiding even
the models that do support the level. Measured: `anthropic` set to `max`
threw for six of its eight models.
Describing what a model can do now reports an unusable profile level as no
default rather than throwing; the request path still refuses it, which is
where a bad configuration belongs. The existing spec asserted the old
throw and now asserts both halves of that split.
Known gap, left deliberately: a model that cannot take the route's level
still fails its first request while the picker shows 「Default」 for it,
because the request path keeps using the profile level as the fallback.
Reaching that needs a hand-written `settings.yaml` — the Models page no
longer writes the field — and the error names the model and the level, so
selecting a supported level is a way out. Closing it properly means giving
`AgentOptions` a `reasoningEffort` so compositions without a model picker
keep an entry point, then dropping the provider-scoped field altogether;
that is its own change.
**Reasoning effort leaves the provider cards entirely.** It is a per-MODEL
capability and the models under one provider disagree about which levels
they accept: setting `anthropic` to `max` made six of its eight models
throw UNSUPPORTED_REASONING_EFFORT, and because the catalog build catches
per provider, the whole provider vanished from the picker behind one error
row. A provider-scoped control can only ever be set to a value some of its
models reject.
The composer's model picker already offers each model its own levels, and
a switch there now records provider, model, and effort together as the
next session's default — so the setting has a better home at the right
granularity. The profile field stays in `settings.yaml` for a deployment
that knows its route; only the control is gone, from both cards and both
adapter families. Two `components.spec` cases used the control as the
vehicle for their op assertions and now use `baseURL`, which is what they
were actually testing.
**A rejected Provider ID now reads as a fault.** It shared the neutral
hint paragraph with the field's guidance, so the copy telling the user
what they got wrong looked like advice. Reuses the existing `.error`
style, matching the split the key field already makes.
