_speakBrowser() was silently failing in two scenarios:
1. Chrome cancel+speak bug: calling speechSynthesis.speak() immediately
after cancel() is silently dropped in Chrome. Fixed by adding a 50ms
setTimeout between cancel() and speak().
2. No voice fallback: when tts_voice preference is empty (never saved)
and the browser has no default 'it-IT' voice, speech fails silently.
Now tries: preferred by name → first Italian voice → first any voice
→ lang-only as last resort.
3. Async voice loading: Chrome/Android load voices asynchronously.
When getVoices() returns empty, now waits for onvoiceschanged (with
a 500ms safety timeout) before speaking.
dadaloop82
1a6e0c87ce
