Previously a brand-new repo (git init, no commits) surfaced `git stash
create: exit status 128: You do not have the initial commit yet` from
deep inside the archive helper. Now the publish flow detects this case
via `git rev-parse --verify HEAD` up front and prints "no commits in
repository; run `git add . && git commit` before publishing". Also
updates the init flow's hint to mention `git init && git commit` so
users aren't misled into thinking `git init` alone is enough.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Pre-existing CLI improvements ahead of the tarball-publish refactor:
- New top-level `ninja scope` command (create, list, set-default).
- `init` accepts no --scope: prompts from ListMyScopes or uses creds default.
- Plugin name prompted if not provided.
- `plugin bump <major|minor|patch>` writes the bumped version into plugin.mod.
- `plugin version` prints the current plugin.mod version.
- `login` prints a URL with ?user_code= so the link is one click.
- creds: HostCreds gains optional default_scope.
- plugin/version: ParseBaseSemver + BumpVersion helpers, with tests.
