fix: Image loading and NN match detail expansion

feat: Add unified Birds & Plants toggle explorer

Add global search query text field and autocomplete suggestions

Add multi-select species chips, year range filter, Search button, fix popover race condition

Subsample to 250k observations for better hover responsiveness and memory usage

Optimize Space: use precomputed similarities and PCA JSON, remove PyTorch and scikit-learn container dependencies

Scale up to full 429k dataset and switch to dataset-based images.tar

add 50k downsampled image thumbnails for native hosting

downsample to 50k and fix 500 internal server error on similarity endpoint

deploy bird explorer dashboard