feat: add ExpiryIndicatorClassic functionality with configuration and rendering

- Implemented ExpiryIndicatorClassic.js for managing expiry dates in SharePoint lists.
- Created classic-elements.xml to define the module for ExpiryIndicator assets.
- Added upgrade-actions-v2.xml to apply the new element manifests.
- Introduced ExpiryModels.test.ts for unit testing the expiry configuration and rules validation.

scripts/Enable-ExpiryIndicator.ps1

@@ -9,7 +9,11 @@ param(
     [Parameter(Mandatory = $true)]
     [string]$ExpiryFieldInternalName,
 
-    [Guid]$FieldCustomizerComponentId = 'a555f4fc-d6a6-4421-8189-457449d9bbde'
+    [Guid]$FieldCustomizerComponentId = 'a555f4fc-d6a6-4421-8189-457449d9bbde',
+
+    [string]$ClassicScriptUrl = '~site/SiteAssets/ExpiryIndicator/ExpiryIndicatorClassic.js',
+
+    [switch]$SkipClassic
 )
 
 $isapiPath = Join-Path ([Environment]::GetFolderPath('CommonProgramFiles')) 'microsoft shared\Web Server Extensions\16\ISAPI'
@@ -41,16 +45,67 @@ try {
     }
     $field.Update()
 
-    # Remove the temporary list-scoped command registration used by older
-    # diagnostic scripts. The app feature owns the production registration.
+    # Remove old diagnostic registrations and make the V2 Classic
+    # registrations idempotent.
     $customActions | Where-Object {
-        $_.Name -eq 'ExpiryIndicator.CommandSet'
+        $_.Name -eq 'ExpiryIndicator.CommandSet' -or
+        $_.Name -eq 'ExpiryIndicator.Classic.ScriptLink' -or
+        $_.Name -eq 'ExpiryIndicator.Classic.Ribbon'
     } | ForEach-Object {
         $_.DeleteObject()
     }
 
     $context.ExecuteQuery()
 
+    if (-not $SkipClassic) {
+        $scriptAction = $list.UserCustomActions.Add()
+        $scriptAction.Name = 'ExpiryIndicator.Classic.ScriptLink'
+        $scriptAction.Title = 'ExpiryIndicator Classic runtime'
+        $scriptAction.Location = 'ScriptLink'
+        $separator = if ($ClassicScriptUrl.Contains('?')) { '&' } else { '?' }
+        $scriptAction.ScriptSrc = $ClassicScriptUrl + $separator + 'expiryField=' + [Uri]::EscapeDataString($field.InternalName)
+        $scriptAction.Sequence = 650
+        $scriptAction.Update()
+
+        $ribbonLocation = if ($list.BaseType -eq [Microsoft.SharePoint.Client.BaseType]::DocumentLibrary) {
+            'Ribbon.Library.Actions.Controls._children'
+        }
+        else {
+            'Ribbon.List.Actions.Controls._children'
+        }
+
+        $ribbonXml = @"
+<CommandUIExtension xmlns="http://schemas.microsoft.com/sharepoint/">
+  <CommandUIDefinitions>
+    <CommandUIDefinition Location="$ribbonLocation">
+      <Button Id="ExpiryIndicator.Classic.ExtendOneYear.Button"
+              Command="ExpiryIndicator.Classic.ExtendOneYear"
+              Sequence="90"
+              LabelText="Ablaufdatum +1 Jahr"
+              Description="Verlängert das Ablaufdatum der ausgewählten Elemente um ein Kalenderjahr."
+              TemplateAlias="o1" />
+    </CommandUIDefinition>
+  </CommandUIDefinitions>
+  <CommandUIHandlers>
+    <CommandUIHandler Command="ExpiryIndicator.Classic.ExtendOneYear"
+                      CommandAction="javascript:ExpiryIndicatorClassic.extendSelected();"
+                      EnabledScript="javascript:ExpiryIndicatorClassic.canExtend();" />
+  </CommandUIHandlers>
+</CommandUIExtension>
+"@
+
+        $ribbonAction = $list.UserCustomActions.Add()
+        $ribbonAction.Name = 'ExpiryIndicator.Classic.Ribbon'
+        $ribbonAction.Title = 'ExpiryIndicator Classic ribbon command'
+        $ribbonAction.Location = 'CommandUI.Ribbon'
+        $ribbonAction.CommandUIExtension = $ribbonXml
+        $ribbonAction.Sequence = 651
+        $ribbonAction.Update()
+
+        $context.ExecuteQuery()
+        Write-Host 'Classic-Ansicht: CSR/JSLink und Ribbon-Befehl wurden registriert.'
+    }
+
     Write-Host "ExpiryIndicator wurde für '$($list.Title)' an '$($field.InternalName)' gebunden."
 }
 finally {