Update helium to 0.14.3.1 and add fastfetch alias

- Bump nixpkgs lock to a newer revision with updated hash.
- Disable fish `generateCompletions` (set to false).
- Add `ff` alias for fastfetch in both bash and fish configurations.

modules/home/bash/aliases.nix

@@ -56,6 +56,7 @@
     kys = "systemctl poweroff";
     jezus = "systemctl reboot";
     ookla = "speedtest";
+    ff = "fastfetch";
     hypr-cli = "hyprctl clients";
 
     # Navigation aliases