feat(transcription): add shared voice input support (#4232)

* feat(webui): add voice transcription input

* feat(webui): render ANSI output in code blocks

* refactor(webui): isolate voice recorder logic

* refactor(transcription): keep websocket ingress thin

* refactor(transcription): resolve channel audio settings on demand

* style(webui): neutralize voice waveform color

* feat(webui): add voice input tooltip

* feat(webui): add voice input keyboard shortcut

* fix(webui): distinguish voice shortcut platforms

* fix(webui): place voice button after model selector

* refactor(webui): share voice hold recording helpers

* fix(desktop): allow microphone voice input

* fix(webui): stabilize token usage month labels

* feat(webui): show voice input on settings overview

* fix(webui): label voice capability as recognition

* fix(webui): align capability overview status

* refactor(webui): isolate transcription socket handling

* fix(webui): soften silent voice waveform

* refactor(audio): clarify transcription service location

* docs(transcription): clarify audio and provider boundaries

* fix(exec): reduce session output polling flake

tests/channels/test_websocket_envelope_media.py

@@ -69,6 +69,7 @@ def _make_channel() -> WebSocketChannel:
     [
         ("data:image/png;base64,AAAA", "image/png"),
         ("data:image/jpeg;base64,AAAA", "image/jpeg"),
+        ("data:audio/webm;codecs=opus;base64,AAAA", "audio/webm"),
         ("data:IMAGE/PNG;base64,AAAA", "image/png"),
         ("data:image/svg+xml;base64,AAAA", "image/svg+xml"),
         ("data:text/plain;base64,AAAA", "text/plain"),