feat: add PowerShell GUI for SharePoint XLS conversion

EventHandlers.ps1

@@ -0,0 +1,15 @@
+# Event handlers for button clicks
+function List-XlsFiles {
+    $script:txtStatus.Text = "Listing XLS files...`n"
+    List-XlsFiles
+}
+
+function Convert-Files {
+    $script:txtStatus.Text += "Starting conversion...`n"
+    Convert-Files
+}
+
+function Move-Files {
+    $script:txtStatus.Text += "Moving files...`n"
+    Move-Files
+}

MainForm.ps1

@@ -0,0 +1,46 @@
+Add-Type -AssemblyName System.Windows.Forms
+Import-Module PnP.PowerShell
+
+# Import our components
+. "$PSScriptRoot\SharePointFunctions.ps1"
+. "$PSScriptRoot\EventHandlers.ps1"
+
+# Create main form
+$form = New-Object System.Windows.Forms.Form
+$form.Text = "SharePoint XLS Converter"
+$form.Size = New-Object System.Drawing.Size(600,400)
+
+# Add controls
+$btnList = New-Object System.Windows.Forms.Button
+$btnList.Location = New-Object System.Drawing.Point(20,20)
+$btnList.Size = New-Object System.Drawing.Size(120,30)
+$btnList.Text = "List XLS Files"
+$form.Controls.Add($btnList)
+
+$btnConvert = New-Object System.Windows.Forms.Button
+$btnConvert.Location = New-Object System.Drawing.Point(160,20)
+$btnConvert.Size = New-Object System.Drawing.Size(120,30)
+$btnConvert.Text = "Convert to XLSX"
+$form.Controls.Add($btnConvert)
+
+$btnMove = New-Object System.Windows.Forms.Button
+$btnMove.Location = New-Object System.Drawing.Point(300,20)
+$btnMove.Size = New-Object System.Drawing.Size(120,30)
+$btnMove.Text = "Move Files"
+$form.Controls.Add($btnMove)
+
+$txtStatus = New-Object System.Windows.Forms.TextBox
+$txtStatus.Location = New-Object System.Drawing.Point(20,70)
+$txtStatus.Size = New-Object System.Drawing.Size(540,280)
+$txtStatus.Multiline = $true
+$txtStatus.ScrollBars = "Vertical"
+$form.Controls.Add($txtStatus)
+
+# Attach event handlers
+$btnList.Add_Click({ List-XlsFiles })
+$btnConvert.Add_Click({ Convert-Files })
+$btnMove.Add_Click({ Move-Files })
+
+# Show form
+$form.Add_Shown({$form.Activate()})
+[void]$form.ShowDialog()

SharePointFunctions.ps1

@@ -0,0 +1,79 @@
+function Connect-SharePoint {
+    param($SiteUrl)
+    try {
+        Connect-PnPOnline -Url $SiteUrl -UseWebLogin
+        return $true
+    }
+    catch {
+        $script:txtStatus.Text += "Error connecting: $_`n"
+        return $false
+    }
+}
+
+function List-XlsFiles {
+    if (-not (Connect-SharePoint -SiteUrl "https://yoursite.sharepoint.com")) {
+        return
+    }
+    
+    $tempLibrary = "Documents/Temp"
+    $fileList = @()
+    
+    $items = Get-PnPListItem -List "Documents" -PageSize 2000 | Where {
+        ($_.FieldValues.FileRef -like "*.xls") -and (-not $_.FieldValues.FileRef.Contains(".xlsx"))
+    }
+    
+    foreach ($item in $items) {
+        $fileList += [PSCustomObject]@{
+            OriginalPath = $item.FieldValues.FileRef
+            TempPath = "$tempLibrary/$($item.FieldValues.FileLeafRef)"
+        }
+    }
+    
+    $fileList | ConvertTo-Json | Set-PnPFileContent -Folder $tempLibrary -FileName "FileList.json"
+    $script:txtStatus.Text += "Found $($fileList.Count) XLS files`n"
+}
+
+function Convert-Files {
+    if (-not (Connect-SharePoint -SiteUrl "https://yoursite.sharepoint.com")) {
+        return
+    }
+    
+    $excel = New-Object -ComObject Excel.Application
+    $excel.Visible = $false
+    
+    try {
+        Get-PnPFile -Url "/sites/yoursite/Documents/Temp/FileList.json" -Path $env:TEMP -Filename "FileList.json"
+        $files = Get-Content "$env:TEMP\FileList.json" | ConvertFrom-Json
+        
+        foreach ($file in $files) {
+            try {
+                $workbook = $excel.Workbooks.Open((Convert-PnPFile -Url $file.OriginalPath -Path $env:TEMP -Filename $file.OriginalFileName))
+                $newName = [System.IO.Path]::ChangeExtension($file.OriginalFileName, ".xlsx")
+                $workbook.SaveAs([System.IO.Path]::Combine($env:TEMP, $newName), 51) # 51 = xlsx
+                Add-PnPFile -Folder "Documents" -Path "$env:TEMP\$newName"
+                $script:txtStatus.Text += "Converted $($file.OriginalFileName) to XLSX`n"
+            }
+            finally {
+                $workbook.Close()
+            }
+        }
+    }
+    finally {
+        $excel.Quit()
+    }
+}
+
+function Move-Files {
+    if (-not (Connect-SharePoint -SiteUrl "https://yoursite.sharepoint.com")) {
+        return
+    }
+    
+    $files = Get-Content "$env:TEMP\FileList.json" | ConvertFrom-Json
+    
+    foreach ($file in $files) {
+        Move-PnPFile -SourceUrl $file.OriginalPath -TargetUrl $file.TempPath -Force
+        $xlsxPath = [System.IO.Path]::ChangeExtension($file.OriginalPath, ".xlsx")
+        Move-PnPFile -SourceUrl "$tempLibrary/$xlsxPath" -TargetUrl $xlsxPath -Force
+        $script:txtStatus.Text += "Moved $($file.OriginalFileName) and its XLSX version`n"
+    }
+}