flake.nix: Add fakeroot requirements so root user can be discovered through (/etc/passwd /etc/group file construction)

Signed-off-by: Thierry Laurion <insurgo@riseup.net>

flake.nix

@@ -142,6 +142,12 @@
           # Git configuration for safe directory access.
           printf '[safe]\n\tdirectory = *\n' >/.gitconfig
           mkdir /tmp; # Temporary directory for various operations.
+
+          # Ensure /etc/passwd and /etc/group exist with root entries
+          echo "root:x:0:0:root:/root:/bin/bash" > /etc/passwd
+          echo "root:x:0:" > /etc/group
+          mkdir -p /root
+          chmod 700 /root
         '';
       };
     });