add hydra, update ruff, format files

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

hydra/jobs.nix

@@ -0,0 +1,19 @@
+{ inputs, outputs }:
+let
+  inherit (inputs.nixpkgs) lib;
+
+  notBroken = pkg: !(pkg.meta.broken or false);
+  isDistributable = pkg: (pkg.meta.license or { redistributable = true; }).redistributable;
+  hasPlatform = sys: pkg: lib.elem sys (pkg.meta.platforms or [ sys ]);
+  filterValidPkgs =
+    sys: pkgs:
+    lib.filterAttrs (
+      _: pkg: lib.isDerivation pkg && hasPlatform sys pkg && notBroken pkg && isDistributable pkg
+    ) pkgs;
+in
+# getCfg = _: cfg: cfg.config.system.build.toplevel;
+{
+  # hosts = lib.mapAttrs getCfg outputs.nixosConfigurations;
+  inherit (outputs) devShells checks formatter;
+  packages = lib.mapAttrs filterValidPkgs outputs.packages;
+}