MIC BROKEN with CallKit: a CallKit call reserves the microphone, so the WebView's
WebRTC can't capture it — calls are unusable until native LiveKit media lands. Add a
server kill-switch (CALLKIT_ENABLED, default OFF) so CallKit can be flipped without an
app rebuild: /api/meetings/config now returns callkit; setupNativeCall bails when off
(-> WebView calls, mic works); push.js only sends VoIP/CallKit pushes when enabled.
Deploying with the flag unset immediately restores working WebView calls.
RE-RING: a late cancel push for an already-declined call hit the plugin's 'unknown
uuid' path and re-reported a fresh incoming call (~1s re-ring). Track endedCalls and
make a late cancel for an already-ended call a no-op.
Server part deploys now (no rebuild); plugin re-ring fix ships with the native build.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>