Amogh/fix: sync profile visibility across sessions and browser refreshes

[Amoghhosamane]

Summary

When a user logs in on a new session or performs a browser refresh, the profile visibility preference was being loaded strictly from the local SharedPreferences cache. Consequently, changes made in a different browser session (e.g. changing privacy to public/private) were not correctly synced.

This PR implements a real-time check against the POD to determine the actual encryption status of existing files (display_name.ttl or profile_picture.ttl) using the isFileEncrypted helper, updating the notifier and updating SharedPreferences dynamically.

Key Changes

• solid_profile_service.dart:
  • Added a private helper _detectPrivacyFromPod() that queries whether display_name.ttl or profile_picture.ttl is encrypted on the POD.
  • Updated loadProfile() to call _detectPrivacyFromPod() after folder setup, dynamically setting the notifier's privacy state and writing it back to local SharedPreferences.
• CHANGELOG.md: Added a changelog entry for this bug fix.

Verification

• Verified that profile visibility syncs correctly when logging in from a clean/incognito session.

Closes #301