Refactor whisper realtime normal recording flow

[hehehai]

Summary

• rework Whisper normal-recording realtime onto the new eager publishing flow and remove Meeting Whisper routing
• add replay and state-machine coverage for Whisper realtime, plus runtime defaults/settings updates for the experimental toggle
• simplify realtime logging and remove stale decode/agreement plumbing after the realtime rewrite

Test plan

• xcodebuild test -project /Users/guanwei/x/doit/Voxt/Voxt.xcodeproj -scheme Voxt -destination 'platform=macOS' -only-testing:VoxtTests/WhisperRealtimeEagerStateTests
• Full realtime replay integration rerun after dependency recompilation
• Manual Whisper realtime recording verification in app