Imaging floor: Standard/Engineer builds report progress past WinPE

The floor's 8 stages are the shopfloor pipeline, and only shopfloor-setup
reports after WinPE, so every gea-standard / gea-engineer build sat at
1/8 forever with no type.

- winpe-status-push.ps1 reads the image from the Z: share mapping when no
  PCTYPE is set and reports those builds as 5 steps.
- Send-ImagingStage.ps1 (deployed to _shared\Applications\extra\pxe-status)
  posts steps 2-5 from the unattend: start and end of specialize, first
  logon, and setup complete (succeeded). It is copied to
  C:\ProgramData\PxeStatus first, because the bulk-enrollment task deletes
  C:\Deploy before first logon. Best-effort: always exits 0.
- Floor rows use Standard/Engineer labels and show the image as the kind.

Tested as SYSTEM in the win11 VM (PowerShell 5.1): the exact unattend
command line, stages 3-5 against a test server, a dead port (exit 0), and
the image regex.

playbook/winpe-status-push.ps1

@@ -52,13 +52,26 @@ if (-not $serial) {
     exit 0
 }
 
+# gea-standard / gea-engineer set no PCTYPE: read the image from the share
+# startnet mapped as Z: (\\server\winpeapps\<image>). Those builds report
+# 5 steps (WinPE, then Send-ImagingStage.ps1 from their unattend); the
+# shopfloor build reports 8.
+$total = 8
+if (-not $PCType) {
+    try {
+        $z = (& net use Z: 2>$null | Out-String)
+        if ($z -match 'winpeapps\\(gea-standard|gea-engineer)\b') { $PCType = $Matches[1]; $total = 5 }
+    } catch { Log "net use Z: exception: $_" }
+    Log "image from Z: = '$PCType'"
+}
+
 # Compose JSON. ConvertTo-Json works in WinPE.
 $payload = @{
     serial        = $serial
     pctype        = $PCType
     current_stage = $CurrentStage
     stage_index   = $StageIndex
-    stage_total   = 8
+    stage_total   = $total
     status        = 'in_progress'
 }
 if ($mac) { $payload.mac = $mac }