Public SSH keys for iscg infra hosts.

Used by `nixos-iscg` flake via sha256-pinned fetchurl on the
`https://git.iscg.dev/mikl.keys` endpoint.

## Hosts

| Host | Key file | Purpose |
|------|----------|---------|
| poppy | poppy.pub | macOS laptop (main) |
| poppy | poppy-legacy.pub | macOS laptop (fallback) |
| lilac | lilac.pub | Android phone |

## Adding a key

1. Generate: ssh-keygen -t ed25519 -C "<host>@<host>" -f ~/.ssh/<host> -N ""
2. Copy .pub here
3. Update table above
4. Add to forgejo account Settings -> SSH Keys