Fix legacy json import compatibility, UI sidebar refactor, and improved test coverage (#4911)

* Fix backward compatibility for old-style JSON config imports

* Refactor sidebar UI generation and add tests for Get-WinUtilVariables

* Fix appnavigation config test following UI generation refactor

* Restore global sync state in variables tests

* fix(impex): migrate supported legacy selections

Keep modern imports strict while allowing legacy backups to skip retired entries with clear logging and user feedback. Add fixtures covering partial and all-retired imports.

* test: strengthen UI and global state coverage

Exercise app category rendering through Initialize-WPFUI and restore global sync without leaking test state.

* fix(impex): ignore legacy metadata fields

Limit legacy selection migration to supported WPF key families so unrelated string metadata does not produce false retired-setting warnings.

* docs: clarify legacy config imports

Distinguish strict modern flat imports from partial legacy object migration, including single-setting export shape and historical groups.

---------

Co-authored-by: Chris Titus <contact@christitus.com>

functions/private/Initialize-WinUtilTabContent.ps1

@@ -14,7 +14,6 @@ function Initialize-WinUtilTabContent {
 
     switch ($TabName) {
         "Install" {
-            Invoke-WPFUIElements -configVariable $sync.configs.appnavigation -targetGridName "appscategory" -columncount 1
             Initialize-WPFUI -targetGridName "appscategory"
 
             Initialize-WPFUI -targetGridName "appspanel"

functions/private/Update-WinUtilSelections.ps1

@@ -3,7 +3,9 @@ function Update-WinUtilSelections {
         [Parameter(Mandatory)]
         [string[]]$flatJson,
 
-        [switch]$Replace
+        [switch]$Replace,
+
+        [switch]$SkipUnknown
     )
 
     $nextSelections = @{
@@ -25,6 +27,10 @@ function Update-WinUtilSelections {
         }
 
         if (-not $listName) {
+            if ($SkipUnknown) {
+                $cbkey
+                continue
+            }
             throw "Unsupported selection key '$cbkey'."
         }
 
@@ -47,12 +53,21 @@ function Update-WinUtilSelections {
         }
 
         if (-not $isKnownSelection) {
+            if ($SkipUnknown) {
+                $cbkey
+                continue
+            }
             throw "Unknown selection key '$cbkey'."
         }
 
         $nextSelections[$listName].Add($cbkey)
     }
 
+    $validSelectionCount = ($nextSelections.Values | ForEach-Object { $_.Count } | Measure-Object -Sum).Sum
+    if ($SkipUnknown -and $validSelectionCount -eq 0) {
+        return
+    }
+
     if ($Replace) {
         foreach ($listName in $nextSelections.Keys) {
             $sync[$listName] = $nextSelections[$listName]

functions/public/Initialize-WPFUI.ps1

@@ -7,10 +7,7 @@ function Initialize-WPFUI {
 
     switch ($TargetGridName) {
         "appscategory"{
-            # TODO
-            # Switch UI generation of the sidebar to this function
-            # $sync.ItemsControl = Initialize-InstallAppArea -TargetElement $TargetGridName
-            # ...
+            Invoke-WPFUIElements -configVariable $sync.configs.appnavigation -targetGridName "appscategory" -columncount 1
 
             # Create and configure a popup for displaying selected apps
             $selectedAppsPopup = New-Object Windows.Controls.Primitives.Popup

functions/public/Invoke-WPFImpex.ps1

@@ -73,15 +73,29 @@ function Invoke-WPFImpex {
                         Write-Error "Failed to load the JSON file from the specified path or URL: $_"
                         return
                     }
-                    if ($null -ne $jsonFile -and $jsonFile.PSObject.Properties['Install']) {
+                    $isLegacyConfig = $jsonFile -is [System.Management.Automation.PSCustomObject] -and
+                        $null -ne $jsonFile.PSObject.Properties["Install"] -and
+                        $null -ne $jsonFile.PSObject.Properties["WPFInstall"]
+                    if ($isLegacyConfig) {
                         Write-WinUtilLog -Component "Impex" -Message "Detected legacy WinUtil config structure; flattening import object."
-                        $flattenedJson = @()
-                        foreach ($prop in $jsonFile.PSObject.Properties) {
-                            if ($prop.Name -ne "Install" -and $null -ne $prop.Value) {
-                                $flattenedJson += @($prop.Value)
+                        # Legacy exports stored checkbox keys in WPFInstall and duplicated package
+                        # source metadata in Install. Current package IDs come from the app catalog,
+                        # so only the selection-key properties are restored.
+                        $flattenedJson = @(
+                            foreach ($property in $jsonFile.PSObject.Properties) {
+                                if ($property.Name -notmatch '^WPF(?:Install|Tweaks|Toggle|Feature|Appx)') {
+                                    continue
+                                }
+
+                                foreach ($selection in @($property.Value)) {
+                                    if ($selection -is [string] -and -not [string]::IsNullOrWhiteSpace($selection)) {
+                                        $selection
+                                    }
+                                }
                             }
-                        }
+                        )
                     } else {
+                        # New style config: flat array of strings
                         $flattenedJson = $jsonFile
                     }
 
@@ -92,9 +106,37 @@ function Invoke-WPFImpex {
                         return
                     }
 
-                    # Build and validate every imported selection before replacing the current
-                    # state. This keeps a malformed config from leaving partial selections behind.
-                    Update-WinUtilSelections -flatJson $flattenedJson -Replace
+                    # Modern configs stay strict. Legacy configs can reference entries that no
+                    # longer exist, so restore supported selections and report the retired keys.
+                    if ($isLegacyConfig) {
+                        $skippedSelections = @(Update-WinUtilSelections -flatJson $flattenedJson -Replace -SkipUnknown)
+
+                        if ($skippedSelections.Count -gt 0) {
+                            $skippedSummary = $skippedSelections -join ", "
+                            Write-WinUtilLog -Component "Impex" -Level "WARN" -Message "Skipped unsupported legacy selections: $skippedSummary"
+                        }
+
+                        if ($skippedSelections.Count -eq @($flattenedJson).Count) {
+                            if ($sync.Form) {
+                                Show-WinUtilMessage -Message "This legacy configuration contains no settings supported by this version of WinUtil. No changes have been made." -Title "Unsupported Legacy Configuration" -Icon "Warning" | Out-Null
+                            }
+                            return
+                        }
+
+                        if ($skippedSelections.Count -gt 0) {
+                            $skippedDisplay = @($skippedSelections | Select-Object -First 10) -join ", "
+                            if ($skippedSelections.Count -gt 10) {
+                                $skippedDisplay += "`n...and $($skippedSelections.Count - 10) more. See the WinUtil log for details."
+                            }
+                            if ($sync.Form) {
+                                Show-WinUtilMessage -Message "Supported settings were imported. The following retired settings were skipped:`n`n$skippedDisplay" -Title "Legacy Configuration Partially Imported" -Icon "Warning" | Out-Null
+                            }
+                        }
+                    } else {
+                        # Build and validate every imported selection before replacing the current
+                        # state. This keeps a malformed config from leaving partial selections behind.
+                        Update-WinUtilSelections -flatJson $flattenedJson -Replace
+                    }
 
                     if ($sync.Form) {
                         Reset-WPFCheckBoxes -doToggles $true