docs/tools/swarmctl-cli.md is rendered by `swarmctl markdown-docs`, and
nix/checks.nix's swarmctl-docs-fresh check diffs the committed copy
against fresh binary output. Enabling prettier on markdown rewrote its
list bullets and footer indentation, which no regeneration can settle:
formatting it fails the freshness check, not formatting it fails
treefmt. .prettierignore already carried hivectl-cli.md for exactly
this reason; swarmctl's doc was added later and the entry was not.
Restore the file to its generated bytes, list it alongside hivectl's,
and state the invariant where the next CLI doc gets added.
cc2503d9c7