Share retained RTT clear dispatch

docs/modernization/build-inventory.md

@@ -589,6 +589,9 @@ powershell -ExecutionPolicy Bypass -File scripts\automation\apple-remote-build.p
   `NodePanelGrid` heightmap draw and bake setup also shares it for active
   texture, depth/blend capability query/apply, viewport query/execution, depth
   clears, and color-write-mask adapter endpoints.
+  Retained RTT clear and masked-clear endpoints also share it for color-mask
+  query/apply, clear-color, and buffer-clear callbacks instead of owning a
+  local raw clear callback cluster.
   Retained desktop HMD eye rendering also routes viewport
   execution through tested backend dispatch.
   Legacy `Texture2D`, `TextureManager`, `Sampler`, and `RTT` public headers no