Linux/X11 (compositing WM): any window change after device creation wedges the Vulkan presenter inside `CreateSwapChain` — fullscreen toggle, border removal, even a bare `SDL_SetWindowPosition`

[jpenberthy]

Release Type: Official Release
Version: 4.3.0.2507
Platform(s): Linux, X11, compositing WM (repro on Cinnamon/Muffin); Windows/D3D11 unaffected

Describe the bug
Every post-device window mutation we tried permanently wedges or crashes the game. Live stacks
(two independent variants) pin the hang inside
SwapChainGraphicsPresenter.Present() → CreateSwapChain() → CreateBackBuffers(), never
returning, ~37% CPU spin. Variants reproduced in one evening, each attempted as the "safer"
fallback for the previous:

1. GameWindow.IsFullscreen = true pre-load → device presents to a black screen forever.
2. Stride borderless path pre-load (FullscreenIsBorderlessWindow + Position + SetSize) →
   window never mapped, Present() at 0 fps, WM kills the "unresponsive" app in ~20 s.
3. Same borderless transition post-load → immediate segfault at the transition frame.
4. Raw SDL_SetWindowFullscreen(FULLSCREEN_DESKTOP) after the loop was pumping → permanent
   wedge with the stack above.
5. Minimal case — SDL_SetWindowBordered(false) + SDL_SetWindowPosition, no size or mode
   change (backbuffer already equaled the display) → same wedge, same stack.

To Reproduce
Code-only Linux game on X11 under a compositing WM; after the first frame, perform any of the
five variants above.

Expected behavior
Fullscreen/borderless transitions work, or fail recoverably.

Additional context
Suspected: the swapchain rebuild waits on in-flight presentation that never completes once the
surface is invalidated under a compositing WM. Working pattern (ships today, worth
documenting for code-only games): construct a fully-shaped GameFormSDL before
Game.Run — border style, final size, final position — so Stride maps the window exactly once
in its final state and builds the swapchain exactly once. Verified on a four-monitor X11
desktop. One repro caveat: poke SDL only through the engine's Silk.NET binding — a raw
DllImport("SDL2") loads a second SDL with uninitialized state and returns garbage bounds.