diff --git a/.github/workflows/wmi-descendants.yml b/.github/workflows/wmi-descendants.yml
index 013e999f..b188c510 100644
--- a/.github/workflows/wmi-descendants.yml
+++ b/.github/workflows/wmi-descendants.yml
@@ -22,12 +22,20 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
-      - name: Existing WMI regression contracts
-        shell: ${{ matrix.shell }}
-        run: ./tests/WmiNamespaceAuditing.Tests.ps1
-      - name: Actual owned namespace tree and cleanup
-        shell: ${{ matrix.shell }}
-        run: ./tests/WmiNamespaceDescendants.Windows.Tests.ps1 -AllowDisposableNamespaceWrite -EvidencePath wmi-descendants-native.json
+      - name: Native tree validation in Windows PowerShell
+        if: matrix.shell == 'powershell'
+        shell: powershell
+        run: |
+          ./tests/WmiNamespaceAuditing.Tests.ps1
+          ./tests/WmiNamespaceDescendants.Tests.ps1
+          ./tests/WmiNamespaceDescendants.Windows.Tests.ps1 -AllowDisposableNamespaceWrite -EvidencePath wmi-descendants-native.json
+      - name: Native tree validation in PowerShell 7
+        if: matrix.shell == 'pwsh'
+        shell: pwsh
+        run: |
+          ./tests/WmiNamespaceAuditing.Tests.ps1
+          ./tests/WmiNamespaceDescendants.Tests.ps1
+          ./tests/WmiNamespaceDescendants.Windows.Tests.ps1 -AllowDisposableNamespaceWrite -EvidencePath wmi-descendants-native.json
       - name: Retain complete native observations
         if: always()
         uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
diff --git a/tests/WmiNamespaceDescendants.Tests.ps1 b/tests/WmiNamespaceDescendants.Tests.ps1
new file mode 100644
index 00000000..52a9c4f9
--- /dev/null
+++ b/tests/WmiNamespaceDescendants.Tests.ps1
@@ -0,0 +1,101 @@
+$ErrorActionPreference='Stop'
+$repo=Split-Path $PSScriptRoot -Parent
+. (Join-Path $repo 'scripts/Configuration.ps1')
+. (Join-Path $repo 'scripts/WmiNamespaceAuditing.ps1')
+$script:assertions=0
+function Assert($v,[string]$m){if(-not $v){throw $m};$script:assertions++}
+function Throws([scriptblock]$f,[string]$m){$yes=$false;try{& $f|Out-Null}catch{$yes=$true};Assert $yes $m}
+function Descriptor([uint32]$flags=32772){[pscustomobject]@{ControlFlags=$flags;Owner='owner';Group='group';DACL=@('a','b');SACL=@();Opaque='preserve'}}
+function Snapshot([string]$ns,$d){[pscustomobject]@{Namespace=$ns;DescriptorJson=(ConvertTo-WelaWmiJson $d);DescriptorMof='native full descriptor';SaclReadPrivilege='test'}}
+function Ace([uint32]$flags=82){[pscustomobject]@{AceType=2;AceFlags=$flags;AccessMask=262175;Trustee=[pscustomobject]@{SIDString='S-1-1-0'}}}
+$script:tree=@{};$script:reads=0;$script:changeAt=0;$script:context='caller/host/source';$script:writes=0
+function Reset {
+ $script:tree=@{'root\default'=(Descriptor);'root\default\A'=(Descriptor);'root\default\A\B'=(Descriptor);'root\default\Protected'=(Descriptor 40964);'root\default\Protected\B'=(Descriptor)}
+ $script:reads=0;$script:changeAt=0;$script:context='caller/host/source';$script:writes=0;$script:prompt=$null
+}
+function Get-WelaWmiChildNames {
+ param($Namespace,$Maximum)
+ @($script:tree.Keys|Where-Object {$_ -clike ($Namespace+'\*') -and $_.Substring($Namespace.Length+1) -notmatch '\\'}|ForEach-Object {$_.Substring($Namespace.Length+1)}|Sort-Object)
+}
+function Get-WelaWmiDescendantContext {$script:context}
+function Get-WelaWmiNamespaceSnapshot {
+ param($Namespace)
+ $script:reads++
+ if($script:changeAt -and $script:reads -eq $script:changeAt){$script:tree['root\default\A'].Owner='racing owner'}
+ if(-not $script:tree.ContainsKey($Namespace)){throw 'Unknown namespace.'}
+ Snapshot $Namespace $script:tree[$Namespace]
+}
+function Set-WelaWmiNamespaceDescriptor {
+ param($Namespace,$ExpectedJson,$Definitions)
+ if((ConvertTo-WelaWmiJson $script:tree[$Namespace]) -cne $ExpectedJson){throw 'Immediate parent drift'}
+ $script:writes++
+ foreach($d in $Definitions){$script:tree[$Namespace].SACL+=Ace $d.AceFlags}
+ $script:tree[$Namespace].ControlFlags=$script:tree[$Namespace].ControlFlags -bor 16
+ # Model the provider's potential inherited-only propagation exactly, leaving protected tree unchanged.
+ foreach($ns in @('root\default\A','root\default\A\B')){$script:tree[$ns].SACL+=Ace;$script:tree[$ns].ControlFlags=$script:tree[$ns].ControlFlags -bor 16}
+}
+function Read-Host {param($Prompt)if($script:prompt){& $script:prompt};'Y'}
+$defs=@(Get-WelaWmiAuditDefinitions -Namespace 'root\default' -IncludeChildren)
+$temp=Join-Path ([IO.Path]::GetTempPath()) ('wela-wmi-desc-test-'+[guid]::NewGuid().ToString('N'))
+try{
+ Reset
+ $before=Get-WelaWmiStableDescendants 'root\default'
+ Assert ($before.Entries.Count -eq 4) 'Complete multilevel inventory.'
+ Assert (@($before.Entries|Where-Object ProtectedBarrier).Count -eq 2) 'Protected ancestor marks whole subtree.'
+ Assert ((Get-WelaWmiDescendantKey $before) -ceq (Get-WelaWmiDescendantKey (Get-WelaWmiStableDescendants 'root\default'))) 'Stable tree key omits observation clock.'
+ $script:changeAt=$script:reads+7
+ Throws {Get-WelaWmiStableDescendants 'root\default'} 'Second-pass descriptor drift must fail.'
+ Reset;$script:tree['root\default\A\bad-child']=Descriptor
+ Assert ((Get-WelaWmiDescendants 'root\default').Status -eq 'Incomplete') 'Ambiguous child name rejected.'
+ Reset;foreach($i in 1..65){$script:tree['root\default\N'+$i]=Descriptor}
+ Assert ((Get-WelaWmiDescendants 'root\default').Status -eq 'Incomplete') 'Count overflow fails rather than truncates.'
+ Reset;$n='root\default';foreach($i in 1..9){$n+='\Deep';$script:tree[$n]=Descriptor}
+ Assert ((Get-WelaWmiDescendants 'root\default').Status -eq 'Incomplete') 'Depth overflow fails rather than truncates.'
+ Reset;$script:tree['root\default\A'].Opaque='x'*2097153
+ Assert ((Get-WelaWmiDescendants 'root\default').Status -eq 'Incomplete') 'Serialized descriptor budget enforced.'
+ Reset
+ $p=@(Get-WelaWmiAuditPlan -Namespace 'root\default' -IncludeChildren)
+ $c=New-WelaConfigurationContext -Auto -DryRun -BackupPath $temp
+ Set-WelaWmiAuditControls $c $p
+ Assert ($script:writes -eq 0 -and $c.Results[0].Status -eq 'Skipped' -and -not (Test-Path $temp)) 'DryRun no state or journal mutation.'
+ $script:tree['root\default\New']=Descriptor
+ $c=New-WelaConfigurationContext -Auto -BackupPath (Join-Path $temp stale)
+ Set-WelaWmiAuditControls $c $p
+ Assert ($script:writes -eq 0 -and $c.Results[0].Status -eq 'Failed') 'Stale membership blocks before journal or setter.'
+ Reset;$p=@(Get-WelaWmiAuditPlan -Namespace 'root\default' -IncludeChildren)
+ $script:prompt={$script:tree['root\default\A'].DACL=@('changed')}
+ $c=New-WelaConfigurationContext -BackupPath (Join-Path $temp prompt)
+ Set-WelaWmiAuditControls $c $p
+ Assert ($script:writes -eq 0 -and $c.Results[0].Status -eq 'Failed') 'Descendant drift during confirmation blocks parent setter.'
+ Reset;$p=@(Get-WelaWmiAuditPlan -Namespace 'root\default' -IncludeChildren)
+ $c=New-WelaConfigurationContext -Auto -BackupPath (Join-Path $temp successful)
+ Set-WelaWmiAuditControls $c $p
+ $result=Complete-WelaConfiguration $c
+ Assert ($script:writes -eq 1 -and $result.ExitCode -eq 0 -and $result.Results[0].Status -eq 'Applied') 'Exact inherited propagation and protected preservation pass.'
+ $ob=$result.Results[0].DescendantVerification.Observation
+ Assert (@($ob.Outcomes|Where-Object Status -eq InheritedAceObserved).Count -eq 2) 'Two inherited readbacks represented.'
+ Assert (@($ob.Outcomes|Where-Object Status -eq ProtectedUnchanged).Count -eq 2) 'Two protected readbacks represented.'
+ $journal=Get-Content (Join-Path $temp successful/before.jsonl)|ConvertFrom-Json
+ Assert ($journal.Before.Descendants.Entries.Count -eq 4 -and $journal.Before.DescriptorMof -eq 'native full descriptor') 'Original journal fields and full subtree retained.'
+ Assert ((Get-WelaWmiDescendantKey $journal.Before.Descendants) -ceq (Get-WelaWmiDescendantKey $p[0].Descendants)) 'Journal serialization does not truncate original child snapshots.'
+ $script:tree['root\default\A'].Opaque='drift'
+ Assert ((Complete-WelaConfiguration $c).ExitCode -eq 1) 'Final child drift propagates failure.'
+ # Each unrelated mutation invalidates observed propagation, even when required ACE still exists.
+ foreach($kind in @('Owner','Dacl','Control','Unknown','Protected','Removed','Extra','Missing','New')){
+  Reset;$a=Get-WelaWmiStableDescendants 'root\default';$null=Set-WelaWmiNamespaceDescriptor 'root\default' $a.Root.DescriptorJson $defs
+  switch($kind){
+   Owner {$script:tree['root\default\A'].Owner='other'}
+   Dacl {$script:tree['root\default\A'].DACL=@('other')}
+   Control {$script:tree['root\default\A'].ControlFlags=$script:tree['root\default\A'].ControlFlags -bor 256}
+   Unknown {$script:tree['root\default\A'].Opaque='other'}
+   Protected {$script:tree['root\default\Protected\B'].SACL+=Ace}
+   Removed {$script:tree.Remove('root\default\A\B')}
+   Extra {$script:tree['root\default\A'].SACL+=Ace 64}
+   Missing {$script:tree['root\default\A'].SACL=@()}
+   New {$script:tree['root\default\Unreviewed']=Descriptor}
+  }
+  $b=Get-WelaWmiStableDescendants 'root\default'
+  Assert ((Test-WelaWmiDescendantOutcomes $a $b $defs).Status -eq 'Unverified') "$kind child change must fail verification."
+ }
+ Write-Host "PASS: $script:assertions bounded WMI descendant assertions."
+}finally{if(Test-Path $temp){Remove-Item $temp -Recurse -Force}}