PhotoPrism's user entity carries a per-user BasePath; the web app now
mirrors that scope client-side so each user sees only their own subtree
in the sidebar, timeline, folder counts, and heap-convert target picker.
Admin without a BasePath is unchanged. Also removes the redundant
"✕ <folder>" pill below the folder tree.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>