feat: Add drum classification and projection update functionality

Commit notes

- Introduced a new `drum_classifier` module for classifying drum types based on audio features. - Updated `_analyze_sample_internal` to classify drum types using the new ML model. - Added a new endpoint `/trigger-projection` to schedule projection updates after bulk changes. - Modified projection scheduling method from PCA to UMAP for improved analysis. - Enhanced the frontend to support multi-selection and deletion of samples, with UI updates for better user experience.

These changes enhance the analysis capabilities and improve sample management in the application.