ClearChat Home v1.6.0 - Final Stability + Release Prep

Focus:
- Improved ZIP updater reliability
- Automatic pre-update database backup
- Rollback copy folder for overwritten files
- Protected config/data/uploads during update
- Updater preflight checks and clearer errors
- System Health + Reliability page improvements
- Database backup restore option
- Backup cleanup controls
- Logo sizing/alignment polish
- Product logo remove/reset support

Note:
Manual update remains the safest method until the ZIP updater has been tested across multiple servers.
