* fix(voice-call): prevent audio overlap with TTS queue
Add a TTS queue to serialize audio playback and prevent overlapping
speech during voice calls. Previously, concurrent speak() calls could
send audio chunks simultaneously, causing garbled/choppy output.
Changes:
- Add queueTts() to MediaStreamHandler for sequential TTS playback
- Wrap playTtsViaStream() audio sending in the queue
- Clear queue on barge-in (when user starts speaking)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* fix(voice-call): use iterative queue processing to prevent heap exhaustion
The recursive processQueue() pattern accumulated stack frames, causing
JavaScript heap out of memory errors on macOS CI. Convert to while loop
for constant stack usage regardless of queue depth.
* fix: prevent voice-call TTS overlap (#1713) (thanks @dguido)
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>
- Switch from inline to URL-based TwiML for outbound calls
- Store TwiML content temporarily and serve on webhook request
- Add twimlStorage map and cleanup helper methods
- Fix TwiML serving to handle CallStatus='in-progress' on initial request
Closes#864
