Migrate hardcoded encrypted files to centralized secret management:
- Replace encrypted domain file with Doppler variable PRIVATE_DOMAIN
- Remove encrypted R2 FUSE script and s3fs password files
- Update hishtory server configuration in commonrc.sh and install script
- Clean up .chezmoiignore for removed encrypted files
This consolidates secret management into Doppler, reducing the number of encrypted files in the repository while maintaining security.