Web voice mode: message readout overlaps and no reliable way to pause #19310

Problem

When using voice mode through the web viewer, messages are read aloud overlapping with each other. There is no reliable way to pause the readout. The user has to resort to muting their phone to stop it.

Expected behavior

• Messages should be read sequentially, not overlapping
• There should be a clear, reliable way to pause/stop the TTS readout mid-stream

Context

Noticed while using voice mode as an overseer interacting with multiple agent sessions. The volume of responses makes the overlap particularly disruptive.