Always On Top: Dedup the alwaysontop command id in window system menu (#45845)

<!-- Enter a brief description/summary of your PR here. What does it
fix/what does it change/how was it tested (even manually, if necessary)?
-->
## Summary of the Pull Request
We picked a command id for always on top, although it has little
possibility, but may collide with other window system menu item, so
before inject, try to see if it persists, if yes, then we don't inject.


<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

- [ ] Closes: #xxx
<!-- - [ ] Closes: #yyy (add separate lines for additional resolved
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

<!-- Provide a more detailed description of the PR, other things fixed,
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
A window with the same id
<img width="1049" height="301" alt="image"
src="https://github.com/user-attachments/assets/ae0ba9b7-c46c-4cbf-8994-e0dc4e5c3527"
/>

You can see there is no always ontop overriding the test item

Normal window:
<img width="468" height="597" alt="image"
src="https://github.com/user-attachments/assets/2ba034a8-c41e-4233-9435-4323c8f1c7a4"
/>

src/modules/alwaysontop/AlwaysOnTop/AlwaysOnTop.cpp

@@ -22,6 +22,7 @@ namespace NonLocalizable
     const static wchar_t* TOOL_WINDOW_CLASS_NAME = L"AlwaysOnTopWindow";
     const static wchar_t* WINDOW_IS_PINNED_PROP = L"AlwaysOnTop_Pinned";
     constexpr UINT SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND = 0xEFE0;
+    constexpr ULONG_PTR SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND_OWNER_TAG = 0x414F5450;
     constexpr DWORD SYSTEM_EVENT_MENU_POPUP_START = 0x0006;
     constexpr DWORD SYSTEM_EVENT_MENU_POPUP_END = 0x0007;
 }
@@ -40,6 +41,29 @@ namespace
 
         hooks.clear();
     }
+
+    bool HasMenuCommand(HMENU menu, UINT commandId) noexcept
+    {
+        return menu && GetMenuState(menu, commandId, MF_BYCOMMAND) != static_cast<UINT>(-1);
+    }
+
+    bool IsAlwaysOnTopMenuCommand(HMENU menu) noexcept
+    {
+        if (!HasMenuCommand(menu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND))
+        {
+            return false;
+        }
+
+        MENUITEMINFOW menuItemInfo{};
+        menuItemInfo.cbSize = sizeof(menuItemInfo);
+        menuItemInfo.fMask = MIIM_DATA;
+
+        return GetMenuItemInfoW(menu,
+                                NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND,
+                                FALSE,
+                                &menuItemInfo) &&
+               menuItemInfo.dwItemData == NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND_OWNER_TAG;
+    }
 }
 
 bool isExcluded(HWND window)
@@ -503,7 +527,7 @@ void AlwaysOnTop::UpdateSystemMenuItem(HWND window) const noexcept
 
     if (!AlwaysOnTopSettings::settings().showInSystemMenu)
     {
-        if (GetMenuState(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND, MF_BYCOMMAND) != static_cast<UINT>(-1))
+        if (IsAlwaysOnTopMenuCommand(systemMenu))
         {
             RemoveMenu(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND, MF_BYCOMMAND);
         }
@@ -513,20 +537,26 @@ void AlwaysOnTop::UpdateSystemMenuItem(HWND window) const noexcept
     auto text = GET_RESOURCE_STRING(IDS_SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP);
     MENUITEMINFOW menuItemInfo{};
     menuItemInfo.cbSize = sizeof(menuItemInfo);
-    menuItemInfo.fMask = MIIM_ID | MIIM_STATE | MIIM_STRING;
+    menuItemInfo.fMask = MIIM_ID | MIIM_STATE | MIIM_STRING | MIIM_DATA;
     menuItemInfo.wID = NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND;
     menuItemInfo.fState = IsPinned(window) ? MFS_CHECKED : MFS_UNCHECKED;
     menuItemInfo.dwTypeData = text.data();
+    menuItemInfo.dwItemData = NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND_OWNER_TAG;
 
-    if (GetMenuState(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND, MF_BYCOMMAND) == static_cast<UINT>(-1))
+    if (!HasMenuCommand(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND))
     {
         InsertMenuItemW(systemMenu, SC_CLOSE, FALSE, &menuItemInfo);
     }
-    else
+    else if (IsAlwaysOnTopMenuCommand(systemMenu))
     {
         menuItemInfo.fMask = MIIM_STATE | MIIM_STRING;
         SetMenuItemInfoW(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND, FALSE, &menuItemInfo);
     }
+    else
+    {
+        Logger::warn(L"Skipping Always On Top system menu command registration because ID 0x{:X} is already in use by another item.",
+                     NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND);
+    }
 }
 
 void AlwaysOnTop::UnpinAll()
@@ -652,8 +682,7 @@ void AlwaysOnTop::HandleWinHookEvent(WinHookEvent* data) noexcept
             }
 
             const auto systemMenu = GetSystemMenu(window, false);
-            return systemMenu &&
-                   GetMenuState(systemMenu, NonLocalizable::SYSTEM_MENU_TOGGLE_ALWAYS_ON_TOP_COMMAND, MF_BYCOMMAND) != static_cast<UINT>(-1);
+            return systemMenu && IsAlwaysOnTopMenuCommand(systemMenu);
         };
 
         HWND commandWindow = nullptr;