Vulkan: extract framebuffer create/destroy to vk_framebuffers.c

- Move vk_create_framebuffers and vk_destroy_framebuffers out of vk.c
- OIT path uses vk_get_main_rasterization_samples() instead of file-local vkSamples
- MSVC vcxproj + filters; document in ARCHITECTURE.md

Co-authored-by: Tim Fox <timfox@outlook.com>

Author: cursoragent

docs/ARCHITECTURE.md

@@ -44,6 +44,7 @@ src/
 │   │   ├── vk_procs.c/h          `qvk*` Vulkan entry points (storage + declarations)
 │   │   ├── vk_shader_modules.c/h SPIR-V `VkShaderModule` creation + `vk_create_shader_modules`
 │   │   ├── vk_pipelines_persistent.c/h Long-lived pipelines (skybox, fog, debug tools)
+│   │   ├── vk_framebuffers.c/h       VkFramebuffer create/destroy (split from vk.c)
 │   │   ├── vk_fluidsim.c/h       Fluid simulation module
 │   │   ├── vk_postfx.c/h         PostFX (SSR, atmosphere, wind)
 │   │   ├── vk_flashlight.c/h     Projected texture system

src/platform/win32/msvc2017/vulkan.vcxproj

@@ -265,6 +265,7 @@
     <ClCompile Include="..\..\..\renderers\vulkan\vk_device.c" />
     <ClCompile Include="..\..\..\renderers\vulkan\vk_flashlight.c" />
     <ClCompile Include="..\..\..\renderers\vulkan\vk_flares.c" />
+    <ClCompile Include="..\..\..\renderers\vulkan\vk_framebuffers.c" />
     <ClCompile Include="..\..\..\renderers\vulkan\vk_frame_end.c" />
     <ClCompile Include="..\..\..\renderers\vulkan\vk_geometry.c" />
     <ClCompile Include="..\..\..\renderers\vulkan\vk_gltf.c" />

src/platform/win32/msvc2017/vulkan.vcxproj.filters

@@ -118,6 +118,9 @@
     <ClCompile Include="..\..\renderers\vulkan\vk_pipelines_persistent.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\renderers\vulkan\vk_framebuffers.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\renderers\common\tr_noise.c">
       <Filter>Source Files</Filter>
     </ClCompile>