feat: add inbound media understanding

Co-authored-by: Tristan Manchester <tmanchester96@gmail.com>

docs/gateway/doctor.md

@@ -111,7 +111,7 @@ Current migrations:
 - `routing.bindings` → top-level `bindings`
 - `routing.agents`/`routing.defaultAgentId` → `agents.list` + `agents.list[].default`
 - `routing.agentToAgent` → `tools.agentToAgent`
-- `routing.transcribeAudio` → `tools.audio.transcription`
+- `routing.transcribeAudio` → `tools.media.audio.models`
 - `bindings[].match.accountID` → `bindings[].match.accountId`
 - `identity` → `agents.list[].identity`
 - `agent.*` → `agents.defaults` + `tools.*` (tools/elevated/exec/sandbox/subagents)