- config: validate port/quality/fps/source/stream-index ranges on load
and before engine start (flinger.Config.Validate)
- discovery: add Announce option to disable multicast (GUI checkbox,
CLI --no-announce); absent JSON key keeps the default true
- backpressure: count dropped frames in the TCP sender, expose via
engine Status and a live counter in the GUI status label
- docs: record M3/M4 decisions and X11 coverage via the portal backend
petere
2b3fd54934