1be91ee7dd
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>