* Changed window.cc to not pass `SDL_WINDOW_OPENGL` for headless opengl graphics modes since this requests a [GLX visual](https://tronche.com/gui/x/xlib/window/visual-types.html#Visual) but CRD's virtual X11 display has no GLX visuals causing window creation to fail with "Couldn't find matching GLX visual".
* Changed `TryLoadEgl` so it fails if `eglBindAPI(EGL_OPENGL_API)` does not return true, causing `CreateFilamentPlatform` to fallback to OSMesa on CRD.
PiperOrigin-RevId: 918029935
Change-Id: Id88338811949b1402578de19bc4d31f4ee1783c1
* Remove the explicit io.Fonts->Build() call from InitImGui, which was deprecated in Dear ImGui v1.92.0. With ImGuiBackendFlags_RendererHasTextures already set, the font atlas is now built lazily by ImGui and communicated to backends via the ImTextureStatus_WantCreate protocol.
* Add proper texture shutdown in ~ImguiBridge by iterating ImGui::GetPlatformIO().Textures and destroying all tracked textures, per the //third_party/dear_imgui/docs/BACKENDS.md instructions.
* Remove the "OK but missing" and "WantUpdates but missing" texture recovery hacks from Update(). These handled a state where ImGui thought textures were alive but the Filament-side storage had been torn down. With proper destruction acknowledgement (SetStatus(Destroyed) + SetTexID(Invalid)), ImGui will now transition destroyed textures to WantCreate on the next frame, and the normal creation path handles it cleanly.
PiperOrigin-RevId: 905886622
Change-Id: Ic449eeaf083740a67eae9c637fb53546a6192b28
Saran Tunyasuvunakool