CVE-2026-63225: Redocly CLI: Path traversal when using `split` command

An OpenAPI or AsyncAPI description could make the split command write files outside the chosen output directory, on the machine of anyone who runs split against it. The write is constrained rather than a free file-write primitive: component data is emitted only as YAML/JSON, and code-sample files are named after the HTTP method, so an attacker can place or overwrite files at an unintended path but has limited control over their name and contents.