The colour dot for a shared (non-owned) local calendar was disabled and the
colour write hit the owner-only PUT /calendars/{id} (404 for recipients). The
dot is now always editable and colour changes go through the dedicated
PUT /calendars/{id}/color endpoint, storing a recipient's own per-user colour
server-side (synced across devices) without granting write or rename. Renaming
stays owner-only. Parity with Android + server.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
c4195243c0