feat: add infrastructure shutdown safeguards and enhance shutdown dialog text

[mdecourcy]

Closes #3830

Paths also touched are via admin access.

[DaneEvans]

looks good. merge for the next internal

[codecov]

Codecov Report

❌ Patch coverage is 0% with 68 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.53%. Comparing base (d83c83c) to head (19d7602).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
...ings/radio/component/ShutdownConfirmationDialog.kt	0.00%	40 Missing ⚠️
...g/meshtastic/feature/settings/radio/RadioConfig.kt	0.00%	25 Missing ⚠️
...e/settings/radio/component/DeviceConfigItemList.kt	0.00%	2 Missing ⚠️
.../org/meshtastic/feature/settings/SettingsScreen.kt	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main   #3858      +/-   ##
========================================
- Coverage   0.53%   0.53%   -0.01%     
========================================
  Files        390     391       +1     
  Lines      22846   22901      +55     
  Branches    2889    2896       +7     
========================================
  Hits         122     122              
- Misses     22703   22758      +55     
  Partials      21      21              

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