doc: server git pull without PATH, keep flakes bootstrap config in repo

- nixos-server.nix: comment for pull when sudo git not found
- readme: add 'Pull when git is not in PATH' and full-path fallback
- add server-configuration-with-flakes.nix for one-time scp to enable flakes

Made-with: Cursor

nixos/server-configuration-with-flakes.nix

@@ -0,0 +1,21 @@
+# One-time: copy to server /etc/nixos/configuration.nix then nixos-rebuild switch (enables flakes for daemon).
+{ config, lib, pkgs, ... }:
+
+{
+  imports = [ ./hardware-configuration.nix ];
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  networking.hostName = "nixos-server";
+  time.timeZone = "Europe/Copenhagen";
+
+  nix.settings.experimental-features = [ "nix-command" "flakes" ];
+
+  users.users.danny = {
+    isNormalUser = true;
+    extraGroups = [ "wheel" ];
+  };
+
+  services.openssh.enable = true;
+}