repaire sentences

sentence_api/translation_jobs.py

@@ -116,6 +116,23 @@ class SubtitleTranslationService:
         except (KeyError, ValueError, AITutorError):
             logger.exception("Could not restart subtitle translation: video=%s", video_hash)
 
+    def start_missing(self, video_hash: str) -> None:
+        """Translate sentences that still lack Chinese text, keeping existing ones."""
+        if not getattr(self.ai_tutor, "available", False):
+            return
+        document = self.repository.get_document(video_hash)
+        if document is None:
+            return
+        if self.snapshot(document).complete:
+            return
+        try:
+            self._start_if_needed(video_hash)
+        except (KeyError, ValueError, AITutorError):
+            logger.exception(
+                "Could not start subtitle translation after gap repair: video=%s",
+                video_hash,
+            )
+
     def admin_snapshot(self, video_hash: str) -> AdminSubtitleTranslationResponse | None:
         current = self.current(video_hash)
         if current is None: