feat(windows): add recoverable existing-agent credential upgrade

agents/windows/tests/Test-MinerOpsEnrollment.ps1

@@ -32,6 +32,9 @@ function Assert-SourceContains {
 Assert-SourceContains 'enrollment\.json' `
     "Bootstrap enrollment file is not explicit."
 
+Assert-SourceContains 'workflow\s*-ne\s*"new_agent"' `
+    "New-Agent bootstrap does not reject transition packages."
+
 Assert-SourceContains '/api/agent/enroll' `
     "Bootstrap does not use the secure enrollment endpoint."
 
@@ -44,8 +47,20 @@ Assert-SourceContains 'agent-config\.json\.pending' `
 Assert-SourceContains 'agent-config\.recovery\.json' `
     "Post-redemption credential recovery path is missing."
 
-Assert-SourceContains 'Protect-MinerOpsCredentialFile' `
-    "Credential file ACL protection is missing."
+Assert-SourceContains 'Open-MinerOpsEnrollmentCredentialFileCreateNew' `
+    "Handle-based credential creation is missing."
+
+Assert-SourceContains 'FileMode\]::CreateNew' `
+    "Credential files are not created with fail-if-present semantics."
+
+Assert-SourceContains 'FileShare\]::None' `
+    "Credential files are not held exclusively while being created."
+
+Assert-SourceContains 'Flush\(\$true\)' `
+    "Credential writes are not durably flushed through the trusted handle."
+
+Assert-SourceContains 'GetNumberOfLinks' `
+    "Enrollment does not reject hard-linked credential targets."
 
 Assert-SourceContains 'S-1-5-18' `
     "SYSTEM ACL entry is missing."
@@ -53,12 +68,73 @@ Assert-SourceContains 'S-1-5-18' `
 Assert-SourceContains 'S-1-5-32-544' `
     "Administrators ACL entry is missing."
 
-Assert-SourceContains 'WindowsIdentity\]::GetCurrent\(\)\.User' `
-    "Installing user ACL entry is missing."
+Assert-SourceContains 'SetOwner\(\$administrators\)' `
+    "Stable Administrators ownership is missing from credential ACLs."
 
-Assert-SourceContains 'Move-Item[\s\S]*\$ConfigPath' `
+Assert-SourceContains '\[IO\.File\]::Move\(\$PendingConfigPath, \$ConfigPath\)' `
     "Atomic final config move is missing."
 
+Assert-SourceContains 'Assert-MinerOpsEnrollmentDirectory' `
+    "Enrollment does not revalidate the directory trust boundary."
+
+Assert-SourceContains 'minerops-filesystem-trust\.blocked-' `
+    "Enrollment directory repair lacks an external durable trust blocker."
+
+Assert-SourceContains 'ApproveFilesystemTrustResetAfterReboot' `
+    "Enrollment lacks an explicit post-reboot trust-reset gate."
+
+Assert-SourceContains 'windows-full-boot-event-v1:' `
+    "Enrollment blockers do not use canonical full-kernel-boot records."
+
+if ($source -match 'LastBootUpTime') {
+    throw "Enrollment must not use a wall-clock boot timestamp."
+}
+
+if ($source -match 'Remove-MinerOpsEnrollmentTrustBlocker') {
+    throw "Enrollment must not have independent trust-blocker deletion authority."
+}
+
+Assert-SourceContains 'Enrollment cannot clear an existing filesystem trust blocker' `
+    "Enrollment does not fail closed on retained filesystem trust blockers."
+
+Assert-SourceContains 'Assert-MinerOpsEnrollmentTrustedAncestors' `
+    "Enrollment does not validate ancestor namespace protection."
+
+foreach ($functionName in @(
+    "Assert-MinerOpsEnrollmentNoReparsePath",
+    "Assert-MinerOpsEnrollmentTrustedAncestors"
+)) {
+    $functionSource = [regex]::Match(
+        $source,
+        "(?s)function $functionName \{.*?\n\}"
+    ).Value
+    if ([string]::IsNullOrWhiteSpace($functionSource)) {
+        throw "$functionName source was not found."
+    }
+    if ($functionSource -notmatch '\$current\s*=\s*\$root') {
+        throw "$functionName does not preserve the filesystem root."
+    }
+    if ($functionSource -notmatch '\$fullPath\.Equals\(\s*\$root') {
+        throw "$functionName does not protect a root-valued full path from trimming."
+    }
+    if ($functionSource -match '\$root\.TrimEnd\(') {
+        throw "$functionName converts a root-qualified path to drive-relative form."
+    }
+    if ($functionSource -match 'GetFullPath\(\$Path\)\.TrimEnd\(') {
+        throw "$functionName trims the filesystem root before identifying it."
+    }
+    if ($functionName -eq "Assert-MinerOpsEnrollmentTrustedAncestors" -and
+        $functionSource -notmatch '\$parent\.Equals\(\s*\$root') {
+        throw "$functionName does not protect a root-valued parent from trimming."
+    }
+}
+
+Assert-SourceContains 'Open-MinerOpsEnrollmentDirectoryLock' `
+    "Enrollment does not lock an insecure target during repair."
+
+Assert-SourceContains 'DirectoryInfo\(\$staging\)' `
+    "Enrollment does not securely stage a new directory."
+
 Assert-SourceContains '& \$Installer' `
     "Bootstrap does not hand off to the safe installer."
 
@@ -68,6 +144,78 @@ Assert-SourceContains 'Start-ScheduledTask -TaskName "MinerOpsAgent"' `
 Assert-SourceContains 'Remove-Item -LiteralPath \$EnrollmentPath' `
     "Consumed extracted enrollment token is not removed."
 
+if ($source -match '\[IO\.File\]::WriteAllText\(\s*\$(Pending|Recovery)ConfigPath') {
+    throw "Enrollment must not truncate or adopt a credential pathname."
+}
+
+$createFunction = [regex]::Match(
+    $source,
+    '(?s)function Open-MinerOpsEnrollmentCredentialFileCreateNew \{.*?\n\}'
+).Value
+$createIndex = $createFunction.IndexOf(
+    'New-MinerOpsEnrollmentProtectedFileCreateNewStream'
+)
+$verifyIndex = $createFunction.IndexOf('Test-MinerOpsEnrollmentCredentialAcl')
+$linkIndex = $createFunction.IndexOf('Assert-MinerOpsEnrollmentSingleLinkStream')
+if (
+    $createIndex -lt 0 -or $verifyIndex -le $createIndex -or
+    $linkIndex -le $verifyIndex -or
+    $createFunction -match 'Set-MinerOpsEnrollmentStreamAcl'
+) {
+    throw "Enrollment credential creation must apply FileSecurity at CreateNew, verify it, then reject links before content."
+}
+
+$createStreamFunction = [regex]::Match(
+    $source,
+    '(?s)function New-MinerOpsEnrollmentProtectedFileCreateNewStream \{.*?\n\}'
+).Value
+foreach ($requiredCreateContract in @(
+    '\[IO\.FileStream\]::new',
+    'FileMode\]::CreateNew',
+    'FileSystemRights\]::WriteData',
+    'FileSystemRights\]::ReadPermissions',
+    'FileSystemRights\]::Synchronize',
+    'FileShare\]::None',
+    '\$Acl'
+)) {
+    if ($createStreamFunction -notmatch $requiredCreateContract) {
+        throw "Enrollment protected CreateNew stream contract is incomplete."
+    }
+}
+if ($createStreamFunction -match 'FullControl|SetAccessControl|Set-Acl') {
+    throw "Enrollment protected creation requests excess rights or repairs by path."
+}
+
+$repairFunction = [regex]::Match(
+    $source,
+    '(?s)function Protect-MinerOpsEnrollmentExistingConfig \{.*?\n\}'
+).Value
+foreach ($requiredRepairRight in @(
+    'ReadPermissions',
+    'ChangePermissions',
+    'TakeOwnership',
+    'Synchronize'
+)) {
+    if ($repairFunction -notmatch $requiredRepairRight) {
+        throw "Enrollment existing-config repair is missing $requiredRepairRight."
+    }
+}
+if ($repairFunction -match 'Set-Acl|FileAccess') {
+    throw "Enrollment existing-config repair must remain handle-bound."
+}
+
+$writeFunction = [regex]::Match(
+    $source,
+    '(?s)function Write-MinerOpsEnrollmentCredentialJson \{.*?\n\}'
+).Value
+if (
+    $writeFunction -notmatch 'Assert-MinerOpsEnrollmentSingleLinkStream' -or
+    $writeFunction -notmatch '\$Stream\.Write' -or
+    $writeFunction -notmatch '\$Stream\.Flush\(\$true\)'
+) {
+    throw "Enrollment credential content is not written and flushed through the verified handle."
+}
+
 $existingConfigGuard = $source.IndexOf(
     'Test-Path -LiteralPath $ConfigPath'
 )
@@ -85,7 +233,7 @@ if (
 }
 
 $configMove = $source.IndexOf(
-    '-Destination $ConfigPath'
+    '[IO.File]::Move($PendingConfigPath, $ConfigPath)'
 )
 
 $installerCall = $source.IndexOf(