feat: harden cljs conversation command plan

[meekmachine]

Summary

• gate CLJS conversation transcription/blink/gaze/prosody commands using agency config
• stop both Vocal and LipSync speech surfaces during interruption, agent end, and conversation stop
• add CLJS smoke coverage for disabled-feature command plans and speech cleanup commands

Validation

• npm run test:cljs
• npm run typecheck
• npm test
• npm run build

Refs #14
Refs #15