NIST RF Dataset Toolkit

Added heatmap generation support for target datasets, including UAV, Car (Sedan, SUV, and Van), and Walking measurements. Improved UI responsiveness for large datasets through faster folder discovery, compact tree loading, and optimized Select All, Deselect All, and automatic file-selection operations.

Added Select All/Deselect All controls, improved handling of empty or invalid AR files, and introduced heatmap-generation logs with processing status and error details.