Cmdpal extension: Powertoys extension for cmdpal (#44006)

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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

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## 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

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

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## Validation Steps Performed
Installer built, and every command works as expected,
Now use sparse app deployment, so we don't need an extra msix

---------

Co-authored-by: kaitao-ms <kaitao1105@gmail.com>

src/modules/MouseUtils/MousePointerCrosshairs/dllmain.cpp

@@ -4,7 +4,8 @@
 #include "trace.h"
 #include "InclusiveCrosshairs.h"
 #include "common/utils/color.h"
-#include <atomic>
+#include <common/utils/EventWaiter.h>
+#include <common/interop/shared_constants.h>
 #include <thread>
 #include <chrono>
 #include <memory>
@@ -124,6 +125,9 @@ private:
     // Mouse Pointer Crosshairs specific settings
     InclusiveCrosshairsSettings m_inclusiveCrosshairsSettings;
 
+    // Event-driven trigger support
+    EventWaiter m_triggerEventWaiter;
+
 public:
     // Constructor
     MousePointerCrosshairs()
@@ -137,11 +141,9 @@ public:
     // Destroy the powertoy and free memory
     virtual void destroy() override
     {
-        UninstallKeyboardHook();
-        StopXTimer();
-        StopYTimer();
+        // Ensure all background threads/handles are torn down before destruction to avoid std::terminate/abort on joinable threads
+        disable();
         g_instance.store(nullptr, std::memory_order_release);
-        // Release shared state so worker threads (if any) exit when weak_ptr lock fails
         m_state.reset();
         delete this;
     }
@@ -203,6 +205,11 @@ public:
         m_enabled = true;
         Trace::EnableMousePointerCrosshairs(true);
         std::thread([=]() { InclusiveCrosshairsMain(m_hModule, m_inclusiveCrosshairsSettings); }).detach();
+
+        // Start listening for external trigger event so we can invoke the same logic as the activation hotkey.
+        m_triggerEventWaiter.start(CommonSharedConstants::MOUSE_CROSSHAIRS_TRIGGER_EVENT, [this](DWORD) {
+            on_hotkey(0); // activation hotkey
+        });
     }
 
     // Disable the powertoy
@@ -215,6 +222,8 @@ public:
         StopYTimer();
         m_glideState = 0;
         InclusiveCrosshairsDisable();
+
+        m_triggerEventWaiter.stop();
     }
 
     // Returns if the powertoys is enabled
@@ -901,4 +910,4 @@ private:
 extern "C" __declspec(dllexport) PowertoyModuleIface* __cdecl powertoy_create()
 {
     return new MousePointerCrosshairs();
-}
+}