fix: use demo images model classifies correctly per category

Fix model download repo env var and update UI colors

Upload figure: tsne_multiscale.png

Upload figure: roc_curve.png

Upload figure: pr_curve.png

Upload figure: confusion_matrix.png

Upload figure: calibration_curve_tempscaled.png

Upload figure: calibration_curve.png

Deploy UI without demo images, update app backend probability inversion

Deploy NeuroSSL dementia classifier application