Moved the group member filter from a top bar into the left sidebar (a
"Mitglieder" section that replaces the personal calendar list while a group is
active). Each member row has a checkbox (show/hide their events) and a colour
dot that opens the colour picker to recolour that member just for this viewer —
stored per-device in localStorage and applied over the server colour. Bumped v44.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
fc00bf9114
