Adds two layers of coverage for the SSH commit-signing path that the
previous commit wires through PlainGitBootstrapper.
TestPlainGitBootstrapper_resolveSigner exercises every branch of the
new dispatcher: nil configuration, GPG-only, SSH-only, encrypted-SSH-
without-passphrase failure, and the documented GPG-wins-when-both-
set precedence.
TestPlainGitBootstrapper_sshSignerProducesVerifiableCommit drives an
end-to-end roundtrip: resolveSigner returns an SSH signer, the signer
plugs into repository.WithSigner, gogit.Client.Commit produces a
commit object, and signature.VerifySSHSignature cryptographically
verifies the gpgsig header against the matching authorized_key.
Catches regressions in the SSH-signing wiring that the dispatcher
unit tests would miss.
Signed-off-by: Hidde Beydals <hidde@hhh.computer>
Hidde Beydals