feat: add certs plugin namespace for certs:add

[valbertovc]

Summary

• Add Certs namespace on App with add(), generate(), remove(), and has_cert
• Integrate certs.add and certs.generate deploy JSON config keys
• Keep legacy generate_cert / cert config and deprecated App.generate_certs aliases
• Bump version to 0.10.0

Stacked on feat/deployment-image (registry, builder, git image deploy, pyproject migration, Python 3.10+, SSH port, CI).

API example

dokku = dokkupy.Dokku('[email protected]')
app = dokku['myapp']
app.certs.add('/path/on/dokku-host/server.crt', '/path/on/dokku-host/server.key')

Deploy config example

{
  "certs": {
    "add": {
      "crt": "/path/on/dokku-host/server.crt",
      "key": "/path/on/dokku-host/server.key"
    }
  }
}

Test plan

• python -m unittest discover -s tests -v (48 tests pass)
• Verify certs:add against a real Dokku host

Made with Cursor