Add PSScriptAnalyzer linting to CI workflow

.github/copilot-instructions.md

@@ -6,12 +6,14 @@ A gallery of startup scripts for **Azure PlayFab Multiplayer Servers (MPS)** tha
 
 ## Linting
 
-Shell scripts are validated with **ShellCheck** (severity: `error`) on every PR and push to `main`. There is no PowerShell linting in CI currently.
-
-Run ShellCheck locally:
+Shell scripts are validated with **ShellCheck** (severity: `error`) and PowerShell scripts with **PSScriptAnalyzer** on every PR and push to `main`.
 
 ```bash
+# Run ShellCheck locally
 shellcheck <script>.sh
+
+# Run PSScriptAnalyzer locally
+pwsh -Command "Invoke-ScriptAnalyzer -Path . -Recurse"
 ```
 
 ## Architecture

.github/workflows/main.yml

@@ -21,4 +21,21 @@ jobs:
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@master
         with:
-          severity: error
+          severity: error
+
+  psscriptanalyzer:
+    name: PSScriptAnalyzer
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Run PSScriptAnalyzer
+        uses: microsoft/psscriptanalyzer-action@v2.0
+        with:
+          path: '*.ps1'
+          recurse: true
+          output: results.sarif
+      - name: Upload SARIF results
+        if: always()
+        uses: github/codeql-action/upload-sarif@v3
+        with:
+          sarif_file: results.sarif