Follow-up split out of #1514 (Auth cleanup), partially addressed by #1531.
Remaining #1514 scope not covered by #1531:
- Remove the Zustand vanilla file-store wrappers — they add complexity without value since no Zustand state management sits above them.
- Add logic to auto-convert existing stored data to plain JSON on read, for backward compatibility with files written by the old wrappers.
Target branch: v2/main.
Follow-up split out of #1514 (Auth cleanup), partially addressed by #1531.
Remaining #1514 scope not covered by #1531:
Target branch: v2/main.