[Feat] (MG_Backend/DirectVulkan): wire glPolygonMode and glColorMaski into pipeline creation

Consume the polygon mode and per-draw-buffer color write masks that the
frontend already tracks, with runtime fallback for the device features
they require.

glPolygonMode:
- Add ConvertPolygonModeToVkEnum (GL_FILL/LINE/POINT -> VkPolygonMode).
- Thread a polygonMode field through PipelineCreatePayload, fold it into
  the pipeline cache hash (distinct modes need distinct pipelines), and
  apply it in PipelineFactory instead of the hardcoded VK_POLYGON_MODE_FILL.
- LINE/POINT require the fillModeNonSolid device feature: detect and
  enable it at device creation, cache m_fillModeNonSolidFeatureEnabled,
  and fall back to FILL at pipeline-build time when it is absent.

glColorMaski:
- The per-attachment color-blend loop now reads GetColorMaskIndexed(i)
  instead of the broadcast GetColorMask(), so each draw buffer gets its
  own write mask (already covered by the pipeline hash).
- Divergent per-attachment masks require independentBlend: cache
  m_independentBlendFeatureEnabled (was enabled but never recorded) and
  fall back to draw buffer 0's mask for every attachment when it is absent.

The internal depth-mipmap utility pipeline keeps VK_POLYGON_MODE_FILL (not
GL-driven). Library builds clean; full SanityTest sweep green (30/30).

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -342,6 +342,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Bool m_multiDrawIndirectFeatureEnabled = false;
         Bool m_shaderDrawParametersExtensionEnabled = false;
         Bool m_shaderDrawParametersFeatureEnabled = false;
+        // fillModeNonSolid gates VK_POLYGON_MODE_LINE/_POINT (glPolygonMode); independentBlend gates
+        // per-draw-buffer color write masks (glColorMaski). Both are cached at device creation and
+        // drive a runtime fallback when the device lacks them.
+        Bool m_fillModeNonSolidFeatureEnabled = false;
+        Bool m_independentBlendFeatureEnabled = false;
         // Cached at device creation from the graphics queue family properties
         // and device limits; drives timer-query support.
         Uint32 m_timestampValidBits = 0;