Sync space code

Fix patch explorer image lookup and DynaDiff loading status

Add union MEI thumbnail support: graceful image skip, entrypoint extraction

Sync explorer: UI improvements, bug fixes, DynaDiff NSD index fix

Replace NSD toggle with RadioButtonGroup, hide dataset dropdown when no compare data

Fix nsd_subset_toggle: always visible, remove ordering-dependent visibility code

Add NSD sub01 subset toggle, union dataset, and dual CLIP embeddings

Sync local changes: CLIP scores, NSD image lookup, multi-trial DynaDiff, phi_c columns, P75 col, label captions, entrypoint pre-warm

Fix DynaDiff VD weights, xformers, and brain thumbnail path resolution

Refactor explorer_app: _State class, extract panel builders, remove phi_mask_toggle

Fix dynadiff structure: diffusers repo in diffusers/ subdir