detect_audio_environment() unconditionally added a hard warning when
running inside a container, blocking /voice on even when the host audio
socket was correctly forwarded (PulseAudio or PipeWire) and sounddevice
could enumerate devices.
Mirror the existing WSL/PulseAudio handling: if PULSE_SERVER or
PIPEWIRE_REMOTE is set, downgrade to a notice and let the audio backend
decide. When neither is set, keep the block but extend the message with
the exact -v / -e flags users need.
Closes#21203