- Create UserCertificate model with validations and certificate renewal logic
- Add tests for UserCertificate model functionality
- Add user certificates fixtures for testing
- Add association between ApiUser and UserCertificates
- Add required gems: dry-types, dry-struct, openssl
- Add /certs to .gitignore
This commit implements the base model for storing user certificates in the
database, including private keys, CSRs, certificates and P12 files. The model
includes basic validation and certificate renewal functionality, with
comprehensive test coverage.
