fix: deadlock on close due to LuaRenderer

[Aurumaker72]

changelog: skip

[Copilot]

Pull request overview

This PR aims to fix an application-close deadlock attributed to LuaRenderer by moving renderer shutdown to a pre-destroy phase while the UI thread is still responsive.

Changes:

• Introduce a new WM_PREDESTROY window message for a staged shutdown sequence.
• Adjust WndProc close flow to close the ROM asynchronously, then trigger WM_PREDESTROY to stop LuaRenderer and destroy the main window.
• Move g_main_ctx.exiting / LuaDialog::close_all() into WM_DESTROY and remove LuaRenderer::stop() from WM_DESTROY.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/Views.Win32/Main.h	Adds WM_PREDESTROY message constant used for staged shutdown.
src/Views.Win32/Main.cpp	Reworks WM_CLOSE/WM_DESTROY handling and adds WM_PREDESTROY to stop LuaRenderer before DestroyWindow.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.