265bdcac82
The prefix is an address: the caller is naming WHICH agent the request is for. With gateway.multiplex_profiles off, _resolve_request_profile ignored the prefix entirely — "don't 404 a would-be valid route" — so a request explicitly addressed to one agent was silently answered by a different one. Observed live (Aug 2026): `hermes peer dm mini/researcher` was answered by the mini's DEFAULT agent with no error on either side, because that host runs one LaunchDaemon per profile and only the default daemon hosted an api_server. A wrong-agent answer is strictly worse than an error: the sender believes the addressee got the message. With multiplexing off the process serves exactly one profile, so the prefix is honored when it names that profile (peers address single-profile daemons this way without knowing the host's topology — get_active_profile_name() is the same identity the file already uses for model resolution) and rejected otherwise through the existing _PROFILE_REJECTED path (404). A process that cannot resolve its own identity rejects too: if it cannot prove who it is, it must not answer as anyone. Unprefixed requests are untouched, and multiplexed hosts are untouched — the change is confined to the prefix-present, multiplexing-off branch that previously discarded the caller's addressing.