Hanging up an UNANSWERED outgoing call re-rang the caller's own phone: the server
sent the "cancel" VoIP push to BOTH parties, and the plugin must reportNewIncomingCall
for every VoIP push (iOS rule) → a phantom ring on the caller who just hung up.
Incoming calls don't hit this (an answered call sends no cancel). Fix: DM cancel goes
only to the callee (not startedBy); group cancel skips the starter.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>