Git credential and SSH key configuration helpers.
Splits out the credential setup helpers from Trebejo.Git.Local so
the local git operations module remains focused on clone/sync/branch
workflows.
Not part of the public API — used only by Trebejo.Git.Local.
Note: Uses System.cmd/3 directly via Trebejo.Util.run_cmd_legacy/3
to avoid a circular dependency with Trebejo.Git.Local.run_git/1 (which
is private).
Summary
Functions
Configures git's credential.helper to the given helper string.
Configures git's core.sshCommand to use the given SSH key path.
Functions
Configures git's credential.helper to the given helper string.
Configures git's core.sshCommand to use the given SSH key path.
Returns :ok on success or {:error, reason} if the key doesn't
exist or git config fails.