Remote targeting

--remote switches scan, fix, discard and guard from local disk to GitHub repositories. Scope is local by default and one scope per run — you always opt in. --user/--org imply --remote, and under --remote a positional must be an owner/repo slug; anything else is a hard error rather than a silently-treated path.

Targets resolve by this ladder, first match wins:

1. ad-hoc selectors — --user / --org and owner/repo positionals (these override config);
2. configured targets.github.users / orgs;
3. your own repositories — the authenticated user's owned repositories (private included), or a GitHub App installation's repositories.