fix(dashboard): release microphone when leaving ODS Talk mid-recording

[patil2001]

Summary

Leaving ODS Talk mid-recording aborted the chat stream but never touched the MediaRecorder: tracks stop only inside its onstop, which fires solely from the button path. Navigating away kept the microphone live and buffering audio. Unmount cleanup now stops the recorder, releasing capture through the existing onstop handler.

AI Assistance

AI-assisted trace of recording teardown paths. The author reviewed the cleanup addition and is responsible for the final diff.

Release Lane

• Stable hotfix targeting release/2.6.x
• Mainline change targeting main
• Next-minor work targeting the next feature/minor release
• Not sure; reviewer should help classify

Stable hotfix reason:

Not targeting the stable release branch directly.

Changed Surface

• Docs only
• Tests only
• Dashboard UI
• Installer
• Core runtime
• Dashboard API
• CI workflows

Validation

• esbuild --loader:.jsx=jsx parse of ODSTalk.jsx - passed.