The speaker picker for live voice down - the ONE operator-readable speaker route.

WHY IT EXISTS. Everything else in this router that lists speakers is require_site_admin (owner or monitoring manager; it was require_owner until the 2026-09-15 decision opened the speaker surface to the monitoring centre's managers), so before this there was no way for an operator to learn the id of a speaker they are already permitted to talk through: the three talk-session routes all take a speaker_id the client must already know, and the event payload carries only a boolean. The picker had no source.

WHY THIS GUARD IS NOT A WIDENING. ESCALATE_VOICE_DOWN already lets its holder MAKE SOUND at this site through POST /speakers/{id}/talk-sessions. Reading the label of the horn they are about to speak through is strictly less than what they can already do, and the response is a minimal projection that deliberately excludes every field describing how we reach the device - see TalkSpeakerResponse, which is a disclosure boundary with the reasoning attached.

{
  "speakers": [
    {
      "label": "SE Horn - dumpster",
      "map_location_label": "SE corner - by the dumpster"
    }
  ]
}