Convert to flake-parts & easy-hosts. Users broke

convert to using flake-parts and easy-hosts for the flake system. This
allows me to remove my poor file-system based code and replace it with
the code done in easy-hosts. Which also has good knock-on effects.

This change factors users out of hosts, which is probably a good change
since users aren't a nixos-module, but aren't completely untangled
either.

I'm going to leave users broken for a minute as I decide exactly how I
want to handle them.

hosts/jibril/default.nix

@@ -0,0 +1,35 @@
+{ config, ... }:
+
+{
+  imports = [
+    ./hardware.nix
+  ];
+  pipewire.enable = true;
+  polkit.enable = true;
+  bluetooth.enable = true;
+  wireless = {
+    enable = true;
+    networks = builtins.fromTOML (builtins.readFile ./networks.toml);
+    secretsFile = config.sops.secrets.wireless.path;
+  };
+
+  sops-nix = {
+    enable = true;
+    keyFile = "/etc/sops/age/keys.txt";
+    sopsFile = ./secrets.yaml;
+    secrets = {
+      wireless = {};
+    };
+  };
+
+  system.timezone = "America/Los_Angeles";
+  system.users.bigWheels = [ "pan" ];
+
+  tuigreet.enable = true;
+  niri.enable = true;
+  
+  postgres.enable = true;
+
+  shell.enabledShells = [ "fish" ];
+  shell.defaultShell = "fish";
+}