fix(ci): verify the binary inside the installers, not the loose target copy

The first fully signed run (signer CN=OLS Digital LLC) signed the app
binary, the MSI, the NSIS installer and the uninstaller, and skipped the
seven build-time DLLs. It still failed verification on
target\release\triple-c.exe. Tauri patches that file with bundle-type
information before each bundle, signs it, packages it, and patches it
again, so the loose copy is unsigned by design and is not what ships.

Verification now:
- checks the installers themselves;
- unpacks the MSI with `msiexec /a` and checks the binaries inside it;
- for NSIS, which can't be unpacked that way, requires the signing log to
  show that the app binary and the uninstaller were signed.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

scripts/windows-verify-signatures.ps1

@@ -1,11 +1,19 @@
-# windows-verify-signatures.ps1 <path-or-wildcard>... - fail unless every file
-# carries a valid, timestamped Authenticode signature.
+# windows-verify-signatures.ps1 <path-or-wildcard>... - fail unless everything
+# that ships carries a valid, timestamped Authenticode signature.
 #
 # The check that makes signing load-bearing rather than hopeful: Tauri skips
 # signing silently in some configurations (no sign command, --no-sign), and an
 # unsigned installer looks exactly like a signed one until SmartScreen blocks
 # it on a user's machine. Every pattern must match at least one file, so a
 # bundle that was never produced cannot pass either.
+#
+# Pass the installers, not target\release\triple-c.exe. The app binary users
+# get is the copy inside each installer: Tauri patches the loose file with
+# bundle-type information before each bundle, signs it, packages it, and
+# patches it again, so the loose copy ends up unsigned by design. The MSI is
+# unpacked with an administrative install and its binaries checked directly;
+# the NSIS installer cannot be unpacked that way, so for it the signing log
+# must show the app binary and the uninstaller were signed.
 
 param([Parameter(Mandatory = $true, ValueFromRemainingArguments = $true)][string[]]$Patterns)
 
@@ -18,49 +26,82 @@ $files = foreach ($pattern in $Patterns) {
     $found
 }
 
-$failed = @()
-foreach ($file in $files) {
-    # signtool's own check: chain to a trusted root under the default
-    # Authenticode policy.
-    # Stop relaxed for the native call, as in windows-sign.ps1.
+function Test-Signature([IO.FileInfo]$File, [string]$Label) {
+    # signtool's own check - chain to a trusted root under the default
+    # Authenticode policy - with Stop relaxed for the native call, as in
+    # windows-sign.ps1.
     $ErrorActionPreference = 'Continue'
-    $verifyOutput = & $env:TRIPLE_C_SIGNTOOL verify /pa $file.FullName 2>&1 | ForEach-Object { "$_" }
+    $output = & $env:TRIPLE_C_SIGNTOOL verify /pa $File.FullName 2>&1 | ForEach-Object { "$_" }
     $signtoolOk = ($LASTEXITCODE -eq 0)
     $ErrorActionPreference = 'Stop'
-    if (-not $signtoolOk) { $verifyOutput | Write-Host }
+    if (-not $signtoolOk) { $output | Write-Host }
 
     # And the timestamp, which signtool verify does not require.
-    $sig = Get-AuthenticodeSignature -FilePath $file.FullName
+    $sig = Get-AuthenticodeSignature -FilePath $File.FullName
     $timestamped = $null -ne $sig.TimeStamperCertificate
-
     if ($signtoolOk -and $sig.Status -eq 'Valid' -and $timestamped) {
-        Write-Host "OK   $($file.Name) - $($sig.SignerCertificate.Subject)"
-    } else {
-        Write-Host "FAIL $($file.Name) - status $($sig.Status), signtool $(if ($signtoolOk) {'ok'} else {'failed'}), timestamped $timestamped"
-        $failed += $file.Name
+        Write-Host "OK   $Label - $($sig.SignerCertificate.Subject)"
+        return $true
+    }
+    Write-Host "FAIL $Label - status $($sig.Status), signtool $(if ($signtoolOk) {'ok'} else {'failed'}), timestamped $timestamped"
+    return $false
+}
+
+function Get-SignedLog {
+    if ($env:TRIPLE_C_SIGN_LOG -and (Test-Path $env:TRIPLE_C_SIGN_LOG)) { return @(Get-Content $env:TRIPLE_C_SIGN_LOG) }
+    return @()
+}
+
+$failed = @()
+$nsisBuilt = $false
+foreach ($file in $files) {
+    if (-not (Test-Signature $file $file.Name)) { $failed += $file.Name }
+    if ($file.FullName -match '\\bundle\\nsis\\') { $nsisBuilt = $true }
+
+    if ($file.Extension -eq '.msi') {
+        $extract = Join-Path ([IO.Path]::GetTempPath()) ('msi-verify-' + [guid]::NewGuid().ToString('N'))
+        $proc = Start-Process msiexec.exe -Wait -PassThru `
+            -ArgumentList '/a', "`"$($file.FullName)`"", '/qn', "TARGETDIR=`"$extract`""
+        $inner = @()
+        if ($proc.ExitCode -eq 0) { $inner = @(Get-ChildItem -Path $extract -Recurse -File -Include *.exe, *.dll) }
+        if ($proc.ExitCode -ne 0) {
+            Write-Host "FAIL $($file.Name) - administrative extract exited $($proc.ExitCode)"
+            $failed += "$($file.Name) (extract)"
+        } elseif ($inner.Count -eq 0) {
+            Write-Host "FAIL $($file.Name) - contains no executable to check"
+            $failed += "$($file.Name) (no executable)"
+        }
+        foreach ($f in $inner) {
+            if (-not (Test-Signature $f "$($file.Name) > $($f.Name)")) { $failed += "$($file.Name) > $($f.Name)" }
+        }
+        Remove-Item -Recurse -Force $extract -ErrorAction SilentlyContinue
     }
 }
 
-# The NSIS uninstaller is signed from inside makensis, which ignores the sign
-# command's exit code, and it ends up embedded in the installer where the
-# checks above cannot reach it. windows-sign.ps1 logs every file it signs; the
-# uninstaller is the one makensis wrote under the job's temp directory (see
-# windows-signing-setup.ps1), so require at least one logged path there.
-$nsisBuilt = @($files | Where-Object { $_.FullName -match '\\bundle\\nsis\\' }).Count -gt 0
+# What the NSIS installer carries but cannot be unpacked here. windows-sign.ps1
+# logs every file it signs. The app binary is signed in place under
+# target\release; the uninstaller is the file makensis wrote under the job's
+# temp directory (see windows-signing-setup.ps1) - and makensis ignores the
+# sign command's exit code for it, so without this a failure there is silent.
 if ($nsisBuilt) {
-    $tmp = $env:TRIPLE_C_SIGN_TMP
-    $log = $env:TRIPLE_C_SIGN_LOG
-    $signedInTmp = @()
-    if ($tmp -and $log -and (Test-Path $log)) {
-        $signedInTmp = @(Get-Content $log | Where-Object { $_.StartsWith($tmp, [StringComparison]::OrdinalIgnoreCase) })
+    $log = Get-SignedLog
+    $appSigned = @($log | Where-Object { $_ -match '\\target\\release\\[^\\]+\.exe$' })
+    if ($appSigned.Count -eq 0) {
+        Write-Host 'FAIL app binary - no signature was logged for it before packaging'
+        $failed += 'app binary'
+    } else {
+        Write-Host "OK   app binary - signed before packaging ($($appSigned.Count)x)"
     }
-    if ($signedInTmp.Count -eq 0) {
-        Write-Host 'FAIL NSIS uninstaller - no successful signature was logged for it'
+    $tmp = $env:TRIPLE_C_SIGN_TMP
+    $uninstaller = @()
+    if ($tmp) { $uninstaller = @($log | Where-Object { $_.StartsWith($tmp, [StringComparison]::OrdinalIgnoreCase) }) }
+    if ($uninstaller.Count -eq 0) {
+        Write-Host 'FAIL NSIS uninstaller - no signature was logged for it'
         $failed += 'NSIS uninstaller'
     } else {
-        Write-Host "OK   NSIS uninstaller - signed as $($signedInTmp[-1])"
+        Write-Host "OK   NSIS uninstaller - signed as $($uninstaller[-1])"
     }
 }
 
 if ($failed.Count -gt 0) { throw "Not validly signed: $($failed -join ', ')" }
-Write-Host "All $(@($files).Count) files are signed and timestamped."
+Write-Host 'Everything that ships is signed and timestamped.'