Floor shows a staged BIOS update from the start of WinPE; NIC speed past 4.29 Gb/s

- winpe-status-push.ps1: check-bios.cmd stages the firmware update before
  the imaging menu, but startnet's 'BIOS firmware update' push only comes
  at the end of WinPE, so builds showed a plain 'Applying image' for the
  whole apply. The first push now reports the staged update when
  X:\bios-fired.flag exists, and the floor shows 'Applying image - BIOS
  update staged' (do not power off during the next reboot). Also: CIM
  fallback for the serial where wmic is missing, and standard/engineer
  always report 5 steps.
- Network pill: cdc_ncm (e.g. the WisdPI RTL8157 5G adapter) keeps link
  speed in a 32-bit bits/s field, so 5 Gb/s reads 705 Mb/s; show the real
  speed with a note.

Tested in the win11 VM (with and without the BIOS flag, and the late
startnet push).

webapp/templates/_imaging_tiles.html

@@ -81,7 +81,11 @@
     {% if stage_idx == 4 and s.status != 'failed' %}{% set warn = True %}{% endif %}
   {% else %}
     {% set friendly = (desk_stage_labels if s.pctype in desk_kind else stage_labels).get(stage_idx, ('Stage ' ~ stage_idx, '')) %}
-    {% if stage_idx == 1 and s.current_stage and 'bios' in s.current_stage|lower %}
+    {% if stage_idx == 1 and s.current_stage and 'bios update staged' in s.current_stage|lower %}
+      {% set friendly = ('Applying image - BIOS update staged',
+          'WinPE staged a firmware update for this model. It flashes during the reboot after the image is applied: do NOT power off then.') %}
+      {% set warn = True %}
+    {% elif stage_idx == 1 and s.current_stage and 'bios' in s.current_stage|lower %}
       {% set friendly = ('Updating BIOS: do not power off',
           'WinPE detected a firmware update for this model. Do NOT power off until the next reboot. Imaging continues afterward.') %}
       {% set warn = True %}