chore(hygiene): final script cleanup and persistence fixes

- Remove remaining obsolete Arch-era scripts (branch-set, debug, upload-log, etc.)
- Add /var/lib/fprint to impermanence persistence for fingerprint survival
- Add /etc/supergfxd.conf to impermanence persistence for GPU mode survival

modules/system/impermanence.nix

@@ -49,12 +49,14 @@ in
         "/var/lib/systemd/coredump"
         "/var/lib/systemd/timesync"
         "/var/lib/bluetooth"
+        "/var/lib/fprint"
         "/etc/NetworkManager/system-connections"
         "/etc/nixos"
         "/etc/ssh"
       ];
       files = [
         "/etc/machine-id"
+        "/etc/supergfxd.conf"
       ];
     };
   };