test(skd): add snapshot tests for new features

- skd-edit: conditionalAppearance with DesignTimeValue/OrGroup/Format
- skd-edit: modify-parameter with use/denyIncompleteValues/availableValue
- skd-edit: set-structure @name= + add-selection Folder() @group=
- skd-compile: availableValues/denyIncompleteValues + Folder in selection
- Fix xsi namespace in @group= XPath query

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.claude/skills/skd-edit/scripts/skd-edit.ps1

@@ -1893,8 +1893,10 @@ switch ($Operation) {
 			if ($groupName) {
 				# Find named StructureItemGroup
 				$dcssetNs = "http://v8.1c.ru/8.1/data-composition-system/settings"
+				$xsiNs = "http://www.w3.org/2001/XMLSchema-instance"
 				$nsMgr = New-Object System.Xml.XmlNamespaceManager($xmlDoc.NameTable)
 				$nsMgr.AddNamespace("dcsset", $dcssetNs)
+				$nsMgr.AddNamespace("xsi", $xsiNs)
 				$groupEl = $settings.SelectSingleNode(".//dcsset:item[@xsi:type='dcsset:StructureItemGroup'][dcsset:name='$groupName']", $nsMgr)
 				if (-not $groupEl) {
 					Write-Host "[WARN] StructureItemGroup `"$groupName`" not found — adding to variant level"