Design entry: hide the silence-cut streaming dictation path behind a per-
workspace settings.ai.dictationStreaming flag, default false, with batch
dictation as the default and fallback. Reuses the existing STT model and
/ai-chat/transcribe — no new provider/model/endpoint fields. Lists the server
+ client touch points, acceptance criteria, and edge cases.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>