feat: support repository authentication modes

[Matthiator]

📝 Summary

Adds catalog support for the repository authentication and config schema changes introduced by kubara PRs #388 and #389.

• supports Git, legacy HTTPS, and OCI repository config paths
• supports HTTPS, SSH, and GitHub App repository secrets
• reads DNS settings from the new v1alpha5 fields while remaining compatible with v1alpha4
• publishes bootstrap and general catalogs as version 1.1.0

🧩 Type of change

• 🔧 CLI / Go code
• 📦 Helm chart
• 🧱 Terraform module
• 📝 Documentation
• 🧪 Test or CI change
• ♻️ Refactor / cleanup

⚠️ Is this a breaking change?

• Yes, this change breaks existing functionality (explain in summary)

🧪 Testing

• CI passed
• Manually tested (local/dev cluster)
• Unit tested
• Not tested (explain why below)

Validated with pre-commit, the catalog source Helm and Terraform checks from #4, and the catalog-backed init/generate, Helm, and Terraform jobs in kubara-io/kubara#388.

🔗 Related Issues / Tickets

Related to kubara-io/kubara#388
Related to kubara-io/kubara#389
Related to #4

✅ Checklist

• Code compiles and passes all tests
• Linting and style checks pass
• Comments added for complex logic
• Documentation updated (if applicable)

📎 Additional Context (optional)

The comprehensive catalog integration workflow is being added in #4. After this PR merges, create bootstrap-v1.1.0 and general-v1.1.0 tags to publish both catalog artifacts.