wzp_oboe_start is a sync FFI call that can block the OS thread
indefinitely waiting on the Android audio HAL. Calling it directly
from an async context freezes all tokio tasks including Rust-side
timeouts. Fix: run it via spawn_blocking so tokio stays responsive.
Also add a 15s Promise.race timeout in JS so a frozen audio_start
surfaces as "connect timed out — check audio permissions" instead of
the join button staying stuck in "Connecting…" forever.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>