Faster shopfloor-setup sync, prompt spacing, XP-era test client

- Deploy shopfloor-setup with rsync instead of the copy module: the
  ~4 GB tree took about 4 minutes on every re-run because copy checksums
  each file. rsync transfers only changes; changed only when it did.
- iPXE drops a trailing space, so 'Machine number:' ran into the typed
  digits. The space now comes from a hex 20 setting.
- tests/vm: pxetest-xp is a permanent client (SeaBIOS, qemu32 32-bit CPU,
  rtl8139, 1 GiB, IDE disk) for the i686 Clonezilla path; start.sh xp.
  Only one client may run at a time across all three.

tests/vm/create.sh

@@ -12,6 +12,10 @@
 #   pxetest-client   2 vCPU, 2 GiB, OVMF Secure Boot with MS keys, 1G blank
 #                    disk, one NIC 52:54:00:9e:10:03 on pxetest-imaging,
 #                    network boot first (UEFI IPv4 PXE).
+#   pxetest-client-nosb  OVMF without Secure Boot, e1000e, 64G SATA disk.
+#   pxetest-xp       XP/Win7-era PC: SeaBIOS (legacy PXE), qemu32 CPU
+#                    (32-bit only), 1 GiB, rtl8139 52:54:00:9e:10:05,
+#                    8G IDE disk.
 #
 # Usage: tests/vm/create.sh
 source "$(dirname "$0")/common.sh"
@@ -51,6 +55,10 @@ if ! vol_exists "$CLIENT_DISK_VOL"; then
     virsh vol-create-as "$POOL" "$CLIENT_DISK_VOL" 1G --format qcow2 >/dev/null
     log "created $CLIENT_DISK_VOL (1G blank)"
 fi
+if ! vol_exists "$CLIENT3_DISK_VOL"; then
+    virsh vol-create-as "$POOL" "$CLIENT3_DISK_VOL" 8G --format qcow2 >/dev/null
+    log "created $CLIENT3_DISK_VOL (8G thin, blank)"
+fi
 vol_exists "$USB_VOL" || log "WARNING: no $USB_VOL volume yet; run build-image.sh before start.sh"
 
 # Disks are type='file' with the pool's path: with type='volume' sources
@@ -202,8 +210,45 @@ XML
     log "defined $CLIENT2_VM"
 fi
 
+# --- third client: XP/Win7-era PC, legacy BIOS, 32-bit CPU ---
+# fallback='forbid': fail rather than quietly give the guest a 64-bit CPU,
+# which would send it down the amd64 Clonezilla path.
+if ! dom_exists "$CLIENT3_VM"; then
+    cat >"$TMP/client3.xml" <<XML
+<domain type='kvm'>
+  <name>$CLIENT3_VM</name>
+  <memory unit='MiB'>$CLIENT3_MEM_MIB</memory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+  </os>
+  <features><acpi/></features>
+  <cpu mode='custom' match='exact'><model fallback='forbid'>qemu32</model></cpu>
+  <clock offset='localtime'/>
+  <devices>
+    <interface type='network'>
+      <source network='$IMAGING_NET'/>
+      <mac address='$CLIENT3_MAC'/>
+      <model type='rtl8139'/>
+      <boot order='1'/>
+    </interface>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2'/>
+      <source file='$POOL_DIR/$CLIENT3_DISK_VOL'/>
+      <target dev='hda' bus='ide'/>
+      <boot order='2'/>
+    </disk>
+    <graphics type='vnc' listen='127.0.0.1' autoport='yes'/>
+    <video><model type='vga'/></video>
+  </devices>
+</domain>
+XML
+    virsh define "$TMP/client3.xml" >/dev/null
+    log "defined $CLIENT3_VM"
+fi
+
 # Never attach a pxetest VM anywhere but default NAT / pxetest-imaging.
-for vm in "$SERVER_VM" "$CLIENT_VM" "$CLIENT2_VM"; do
+for vm in "$SERVER_VM" "${ALL_CLIENTS[@]}"; do
     while read -r _ type src _ _; do
         case "$type:$src" in
             network:"$GE_NET") [ "$vm" = "$SERVER_VM" ] || die "$vm is on $GE_NET" ;;