Add build.ps1 -CommitArtifacts switch for source/artifact lockstep commits

New switch stages and commits only the three build-output paths (Module/PSInfisicalAPI/bin/**, Module/PSInfisicalAPI/PSInfisicalAPI.psd1, CHANGELOG.md) with a message referencing the embedded BuildCommitHash. Mutually exclusive with -CommitOnSuccess. README and CHANGELOG updated to document the recommended two-commit workflow.

build.ps1

@@ -15,9 +15,15 @@ param(
 
     [switch]$CommitOnSuccess,
 
+    [switch]$CommitArtifacts,
+
     [switch]$Force
 )
 
+if ($CommitOnSuccess.IsPresent -and $CommitArtifacts.IsPresent) {
+    throw "-CommitOnSuccess and -CommitArtifacts are mutually exclusive."
+}
+
 $ErrorActionPreference = 'Stop'
 Set-StrictMode -Version Latest
 
@@ -390,4 +396,30 @@ if ($CommitOnSuccess.IsPresent) {
     if ($LASTEXITCODE -ne 0) { throw "git commit failed." }
 }
 
+if ($CommitArtifacts.IsPresent) {
+    Write-Step "Committing build artifacts (embedded BuildCommitHash=$commitHash)"
+    $artifactPaths = @(
+        [System.IO.Path]::Combine('Module', 'PSInfisicalAPI', 'bin'),
+        [System.IO.Path]::Combine('Module', 'PSInfisicalAPI', 'PSInfisicalAPI.psd1'),
+        'CHANGELOG.md'
+    )
+
+    foreach ($artifactPath in $artifactPaths) {
+        & git -C $RepositoryRoot.FullName add -- $artifactPath
+        if ($LASTEXITCODE -ne 0) { throw "git add '$artifactPath' failed." }
+    }
+
+    $stagedOutput = & git -C $RepositoryRoot.FullName diff --cached --name-only
+    if ($LASTEXITCODE -ne 0) { throw "git diff --cached failed." }
+    $stagedFiles = @($stagedOutput | Where-Object { -not [string]::IsNullOrWhiteSpace($_) })
+    if ($stagedFiles.Count -eq 0) {
+        Write-Step "No build artifact changes to commit."
+    } else {
+        $subject = "Build artifacts for $commitHash"
+        $body    = "Auto-generated by build.ps1 -CommitArtifacts. Build $buildVersion. Module DLL and manifest embed BuildCommitHash=$commitHash, matching the source commit they were produced from."
+        & git -C $RepositoryRoot.FullName commit -m $subject -m $body
+        if ($LASTEXITCODE -ne 0) { throw "git commit failed." }
+    }
+}
+
 Write-Step "Build complete."