Add training monitor implementation

Signed-off-by: Felipe Cardoso <felipe.cardoso@hotmail.it>

backend/app/models/training.py

@@ -9,6 +9,9 @@ class TrainingStatus(BaseModel):
     total_steps: int
     loss: float
     learning_rate: float
+    percentage: float
     eta_seconds: Optional[float]
     steps_per_second: float
     updated_at: datetime
+    source: str  # 'local' or 'remote'
+    source_path: str