After each training run, the Character Error Rate (CER = 1 - accuracy), loss, accuracy, and epoch count are now stored on the OcrTrainingRun record and shown in the training history table. Also adds the missing POST /api/ocr/segtrain endpoint and the triggerSegTraining service method so the segmentation training card can actually trigger training. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>