Powertoys Extension: Trigger latest layout/monitor refresh for fancyzone in cmdpal extension (#44756)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
Best effort trigger refresh for the monitor/layout refresh for
fancyzones, user may experience error for first time run but will get
correct result in next visit.

This bring better experience than the always-stale-state, while still
remain performant command.

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## PR Checklist

- [ ] Closes: #xxx
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issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
Validated locally that second time visit will bring correct monitor when
plug/unplug monitor

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.PowerToys/Helpers/FancyZonesDataService.cs

@@ -41,16 +41,13 @@ internal static class FancyZonesDataService
 
         try
         {
-            if (!File.Exists(FZPaths.EditorParameters))
-            {
-                error = Resources.FancyZones_MonitorDataNotFound;
-                Logger.LogWarning($"TryGetMonitors: File not found. Path={FZPaths.EditorParameters}");
-                return false;
-            }
-
-            Logger.LogInfo($"TryGetMonitors: File exists, reading...");
-            var editorParams = FancyZonesDataIO.ReadEditorParameters();
-            Logger.LogInfo($"TryGetMonitors: ReadEditorParameters returned. Monitors={editorParams.Monitors?.Count ?? -1}");
+            // Request FancyZones to save current monitor configuration.
+            // The editor-parameters.json file is only written when:
+            // 1. Opening the FancyZones Editor
+            // 2. Receiving the WM_PRIV_SAVE_EDITOR_PARAMETERS message
+            // Without this, monitor changes (plug/unplug) won't be reflected in the file.
+            var editorParams = ReadEditorParametersWithRefresh();
+            Logger.LogInfo($"TryGetMonitors: ReadEditorParametersWithRefreshWithRefresh returned. Monitors={editorParams.Monitors?.Count ?? -1}");
 
             var editorMonitors = editorParams.Monitors;
             if (editorMonitors is null || editorMonitors.Count == 0)
@@ -74,6 +71,23 @@ internal static class FancyZonesDataService
         }
     }
 
+    /// <summary>
+    /// Requests FancyZones to save the current monitor configuration and reads the file.
+    /// This is a best-effort approach for performance: we send the save request and immediately
+    /// read the file without waiting. If the file hasn't been updated yet, the next call will
+    /// see the updated data since FancyZones processes the message asynchronously.
+    /// </summary>
+    private static EditorParameters.ParamsWrapper ReadEditorParametersWithRefresh()
+    {
+        // Request FancyZones to save the current monitor configuration.
+        // This is fire-and-forget for performance - we don't wait for the save to complete.
+        // If this is the first call after a monitor change, we may read stale data, but the
+        // next call will see the updated file since FancyZones will have processed the message.
+        FancyZonesNotifier.NotifySaveEditorParameters();
+
+        return FancyZonesDataIO.ReadEditorParameters();
+    }
+
     public static IReadOnlyList<FancyZonesLayoutDescriptor> GetLayouts()
     {
         Logger.LogInfo($"GetLayouts: Starting. LayoutTemplatesPath={FZPaths.LayoutTemplates} CustomLayoutsPath={FZPaths.CustomLayouts}");

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.PowerToys/Helpers/FancyZonesNotifier.cs

@@ -10,13 +10,25 @@ namespace PowerToysExtension.Helpers;
 internal static class FancyZonesNotifier
 {
     private const string AppliedLayoutsFileUpdateMessage = "{2ef2c8a7-e0d5-4f31-9ede-52aade2d284d}";
+    private const string SaveEditorParametersMessage = "{d8f9c0e3-5d77-4e83-8a4f-7c704c2bfb4a}";
+
     private static readonly uint WmPrivAppliedLayoutsFileUpdate = RegisterWindowMessageW(AppliedLayoutsFileUpdateMessage);
+    private static readonly uint WmPrivSaveEditorParameters = RegisterWindowMessageW(SaveEditorParametersMessage);
 
     public static void NotifyAppliedLayoutsChanged()
     {
         _ = PostMessageW(new IntPtr(0xFFFF), WmPrivAppliedLayoutsFileUpdate, UIntPtr.Zero, IntPtr.Zero);
     }
 
+    /// <summary>
+    /// Notifies FancyZones to save the current monitor configuration to editor-parameters.json.
+    /// This is needed because FancyZones only writes this file when opening the editor or when explicitly requested.
+    /// </summary>
+    public static void NotifySaveEditorParameters()
+    {
+        _ = PostMessageW(new IntPtr(0xFFFF), WmPrivSaveEditorParameters, UIntPtr.Zero, IntPtr.Zero);
+    }
+
     [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
     private static extern uint RegisterWindowMessageW(string lpString);