Crash fix after diff and closing a model

[darko1979]

This fix resolves issue #1872 where pgmodeler was crashing after I diff and then trying to close main window.
Also this fixes another crash I started noticing on version 2.0, after opening a model and then trying to close it from menu it will crash pgmodeler.

Fix was copilot assisted and it was hard to trace because it was not reproducible when debugger was attached. So copilot added stack trace for windows (included in second commit) and from that stack trace was able to locate the problem.

Stack trace before:

** Stack trace unavailable on Windows system **

stack trace now:

** pgModeler crashed after receive signal: 11 **

Date/Time: 2026-03-13 11:43:19 
Version: 2.0.0-alpha1 
Build: 20260313.20260313 
Compilation Qt version: 6.10.1
Running Qt version: 6.10.1

Executable: C:\pgmodeler-2.0.0-alpha1\pgmodeler.exe

[25] pgmodeler.exe+0x6622
[24] ntdll.dll+0x8ce46
[23] ntdll.dll+0xa296f
[22] ntdll.dll+0x52554
[21] ntdll.dll+0xa147e
[20] libcore.dll+0x1d050
[19] libcore.dll+0x1190b
[18] libcore.dll+0x6d27d
[17] libcore.dll+0x6c639
[16] libcore.dll+0x6d8cd
[15] Qt6Core.dll+0xd8a50
[14] Qt6Widgets.dll+0x6058
[13] pgmodeler.exe+0x53ef
[12] Qt6Core.dll+0x91b38
[11] Qt6Core.dll+0x9587c
[10] Qt6Gui.dll+0x4769d2
[9] Qt6Core.dll+0x26d17d
[8] Qt6Gui.dll+0x4769a9
[7] Qt6Core.dll+0x9df75
[6] Qt6Core.dll+0x9b5b2
[5] pgmodeler.exe+0x26b8
[4] pgmodeler.exe+0x6d6a
[3] pgmodeler.exe+0x10d9
[2] pgmodeler.exe+0x1436
[1] KERNEL32.DLL+0x17374
[0] ntdll.dll+0x4cc91

[rkhaotix]

Hi @darko1979

Thanks for the PR.

I fear that the windows stacktrace code is not so efficient to pinpoint problems, compared to the stack trace in Linux and macOS. I tried to write a similar code some weeks ago, but gave up because the returned info was not as detailed as I thought. I'll try another approach in the future.

About the crash fix, I'll merge it, but could you please separate it into a different PR? :)

[darko1979]

@rkhaotix done.