Sync iOS Contact Groups ("Lists") to Dex

Currently, contact groups (called “Lists” in iOS) do not sync into Dex when using the two-way sync. Many users already have well-organized groups in their iOS address book, and losing that structure on import is frustrating and time-consuming.

This feature would allow Dex to import and sync iOS contact groups, either as Dex groups or as tags, preserving the user’s existing organization. It should also keep group memberships updated as contacts are added/removed on either side (if technically possible through CardDAV or other means).