- Launch audio ticker (50pps Opus PT=111) and STUN consent freshness
as background goroutines in WebRTC mode
- Fix STUN infinite ping-pong: only respond to Binding Requests (0x0001),
not Binding Responses (0x0101)
- Add decoy send delay (2-8ms) to avoid burst timing fingerprint
- Use shared atomic transport-cc counter across all streams
- WebRTC mode uses compound RTCP (SR+SDES) instead of bare SR
- Server responds to client STUN Binding Requests with proper Response
DPI score: 55.6 -> 73.8 (timing 10->69, size CV 0.09->0.93)