Offer Whisper's Translate to English only on models trained for it (canTranslate)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/WorkBreakdown.md

@@ -65,6 +65,8 @@ Notes (M1):
       surface active backend in UI
 - [x] Handle model switching (dispose old pipeline, load new)
 - [x] Language / task options for multilingual models (transcribe vs translate)
+- [x] Whisper translate only on models trained for it (`canTranslate`; hidden for
+      large-v3-turbo and `.en`, stale "translate" resets to transcribe — D-WS4a)
 - [~] Verify quantized variants (q4/q8/fp16) on both backends; record working
       combinations in `models.ts`