fix: skip removable/USB disks in %pre, wait for NVMe init

JetKVM virtual media appears as /dev/sda before NVMe initializes.
Now: wait up to 10s for disks, skip removable disks and anything
under 20GB. Fixes "ignoredisk: sda does not exist" on SER9MAX.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bastion/src/bastion/src/templates/install.ks.ts

@@ -88,8 +88,20 @@ chmod 440 /etc/sudoers.d/${adminUser}`;
   const diskLine = disk
     ? `DISK="${disk}"`
     : `DISK=""
-for d in /dev/nvme0n1 /dev/sda /dev/vda; do
-    [ -b "$d" ] && { DISK="$(basename $d)"; break; }
+# Wait up to 10s for NVMe/SCSI disks to appear (they init async in initrd)
+for _wait in $(seq 1 10); do
+    for d in /dev/nvme0n1 /dev/sda /dev/vda; do
+        [ -b "$d" ] || continue
+        # Skip removable disks (USB, CD-ROM, JetKVM virtual media)
+        _bname=$(basename "$d")
+        [ -f "/sys/block/$_bname/removable" ] && [ "$(cat /sys/block/$_bname/removable)" = "1" ] && continue
+        # Skip disks smaller than 20GB (likely USB sticks)
+        _size=$(cat /sys/block/$_bname/size 2>/dev/null || echo 0)
+        [ "$_size" -lt 41943040 ] && continue
+        DISK="$_bname"
+        break 2
+    done
+    sleep 1
 done
 [ -z "$DISK" ] && { echo "ERROR: no disk found"; exit 1; }`;