Review follow-up for #112359:
- gateway `_format_session_info` (the /model info block) printed only
`Model: <preset> / Provider: moa`, so the messaging surfaces still hid
who pays; append the same "Acting model (billed for the run)" line the
CLI switch summary prints.
- `_provider_mismatch_notice` compared providers case-sensitively and
treated the routing pseudo-provider `auto` as a billing seat, printing a
misleading "not to OpenAI" / "not to auto" line; lower-case both sides
and skip `auto`.
- "references only advise once per user turn" is only true for the
default `fanout: user_turn`; say "by default" on the inventory row, the
`hermes moa list` header, the Desktop pill/description (en/zh/zh-hant)
and the docs line.
c8f0f6b136