AudioLink 0.2.1 preview — bus return fader and both installers

AudioLink 0.2.1 preview — one channel, bus return fader, both installers

The release contains the Receiver installer, OBS sender installer, and a
combined portable ZIP with both apps in separate folders. Use the receiver on
the VoiceMeeter PC and the OBS sender on the OBS PC. OBS is not required on the receiver PC.

Changes

• Callback now says Pick one channel only and uses radio buttons. Choose one
  input strip OR one A bus. Potato offers In 1–In 8 / A1–A5; Banana In 1–In 5 / A1–A3.
• Bus return level adjusts only AudioLink's return, from 0 dB down to mute.
  Changes apply live, with a smooth transition and no reconnect. Other bus audio
  remains unchanged. The setting is saved and retained by tray Refresh.
• The matching OBS sender reports Callback output and its processed frame count
  instead of displaying VBAN-only status for that mode.
• Existing OBS senders still work. Pairing and the network protocol are unchanged.

Updating

Choose Shut down in the receiver tray menu before installing. Close OBS before
running the sender installer and select the OBS root folder containing bin/64bit/obs64.exe.
Pairing and VBAN settings are retained. If several callback destinations were saved
in 0.2.0, select one channel again and press Start / apply. The bus fader works
immediately; changes to the destination or output mode still require Start / apply.

The installers are unsigned. SHA-256 checksums are included. Automated checks cover
single-channel routing, return-only gain and mute, settings migration, transport,
OBS sender compatibility, and isolated installer payloads. Live callback listening
and final device routing still need confirmation on the target PC.

Full setup
· Callback and fader guide