[P3-T3] Conduct Hyperparameter Tuning

[edaaydinea]

• Description: For the top 1-2 performing models, use GridSearchCV or RandomizedSearchCV to find the optimal hyperparameters. Track these tuning jobs as nested runs in MLflow.
• Acceptance Criteria: The best model's hyperparameters are identified and a final, tuned model is trained and registered in the MLflow Model Registry.