Default API key role was "admin", which was something that I forgot to fix during testing. We
change it to "read-only".
Additionally repository URLs now reject `file://` scheme (another testing artifact) localhost,
private IP ranges, and cloud metadata endpoints. Nix expressions reject path traversal (`..`)
and absolute paths. Validation is called at the evaluator endtrypoint before command construction.
Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I35729c6aa9ec4ff8d1ea19bd57ea93646a6a6964
