chore: centralise folders

files/scripts/fs-diff.sh

@@ -0,0 +1,20 @@
+set -euo pipefail
+
+OLD_TRANSID=$(sudo btrfs subvolume find-new /mnt/root-blank 9999999)
+OLD_TRANSID=${OLD_TRANSID#transid marker was }
+
+sudo btrfs subvolume find-new "/mnt/root" "$OLD_TRANSID" |
+    sed '$d' |
+    cut -f17- -d' ' |
+    sort |
+    uniq |
+    while read -r path; do
+        path="/$path"
+        if [ -L "$path" ]; then
+            : # The path is a symbolic link, so is probably handled by NixOS already
+        elif [ -d "$path" ]; then
+            : # The path is a directory, ignore
+        else
+            echo "$path"
+        fi
+    done