Fix XSS vulnerability in PATH environment variable rendering (#432)

* Initial plan

* Fix XSS vulnerability by HTML-encoding before replacing delimiters

Co-authored-by: bart-vmware <[email protected]>

* Remove unnecessary null-conditional operator after Html.Encode

Co-authored-by: bart-vmware <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: bart-vmware <[email protected]>

Author: Copilot

Configuration/src/ConfigurationProviders/Views/Home/PlaceholderValues.cshtml

@@ -15,11 +15,11 @@
             <td>
                 @if (Platform.IsWindows)
                 {
-                    @Html.Raw(Model.ResolvedFromPathEnvironmentVariable?.Replace(";", "<br/>"))
+                    @Html.Raw(Html.Encode(Model.ResolvedFromPathEnvironmentVariable).Replace(";", "<br/>"))
                 }
                 else
                 {
-                    @Html.Raw(Model.ResolvedFromPathEnvironmentVariable?.Replace(":", "<br/>"))
+                    @Html.Raw(Html.Encode(Model.ResolvedFromPathEnvironmentVariable).Replace(":", "<br/>"))
                 }
             </td>
         </tr>