Step 3 of the Tauri Android rewrite was still returning "audio backend not
yet wired on Android (step 3)" because the cfg-gated Android stubs for
connect/disconnect/toggle_mic/toggle_speaker/get_status were shadowing the
real commands. Now that CallEngine::start() has a real Android body (phase
3, commit fdbe502), the gates are unnecessary.
- Drop the #[cfg(not(target_os = "android"))] gates from all five
engine-backed Tauri commands.
- Delete the Android stub block (~50 LOC of "not connected" boilerplate).
- Ungate `use engine::CallEngine;` and the AppState.engine field so both
targets share the same Mutex<Option<CallEngine>>.
- CallEngine::stop() now calls crate::wzp_native::audio_stop() on Android so
the mic + speaker are released between calls, matching the desktop
behaviour where dropping _audio_handle tears down CPAL.
Direct-call flow on Android: peer sends DirectCallOffer → user accepts via
answer_call → relay sends signal "setup" event → main.ts auto-invokes
connect(relay, room) → CallEngine::start() runs the Android branch →
wzp_native::audio_start() brings up Oboe → send/recv tasks stream PCM
through the dlopen boundary.
5beea7de40