Standard/Engineer builds are done at OOBE on the imaging floor

Everything after OOBE needs the employee to log in, which happens off the
PXE network, so the floor waited forever at step 3 of 5. Now 3 steps:
WinPE, Windows setup installing apps, ready at OOBE (succeeded).

- both unattends: specialize Order 49 posts step 3 as succeeded
  (Path 182 chars; lint clean). Only that line changed.
- Send-ImagingStage.ps1: StageTotal 3; steps above the total (the old
  first-logon steps 4 and 5 still in the unattends) are logged and not
  posted, so they cannot reopen a finished build
- winpe-status-push.ps1: total 3 for gea-standard / gea-engineer
- floor tile step 3: "Ready at OOBE"

Tested in the win11 VM against the test server: steps 2 and 3 post,
step 3 shows succeeded, step 4 is skipped. Not deployed: the unattends
go out only through scripts/deploy-unattend.sh.

webapp/templates/_imaging_tiles.html

@@ -18,11 +18,13 @@
 } %}
 
 {# gea-standard / gea-engineer builds: WinPE push, then
-   Send-ImagingStage.ps1 from the image's unattend; stage_total 5. #}
+   Send-ImagingStage.ps1 from the image's unattend; stage_total 3. Done
+   at OOBE: everything after needs the employee's logon, off the PXE
+   network. (4 and 5 are kept for builds still running the old unattend.) #}
 {% set desk_stage_labels = {
     1: ('Applying Windows image',        'WinPE loaded - PESetup is applying the Windows image to disk.'),
     2: ('Windows setup: installing apps','First boot (specialize): certificates, WiFi, fonts, Adobe, Java and the enrollment task.'),
-    3: ('Waiting for first logon',       'Apps installed. Windows setup finishes when someone logs on to the PC.'),
+    3: ('Ready at OOBE',                 'PXE imaging is done. Hand the PC to the employee: first logon (and the engineering layer on Engineer builds) runs when they sign in.'),
     4: ('First logon',                   'First logon commands running (the engineering layer on Engineer builds).'),
     5: ('Setup complete',                'Imaging is done; bulk enrollment continues on the PC.')
 } %}