Move canvas stroke commit GL mappings to renderer gl

docs/modernization/build-inventory.md

@@ -218,6 +218,9 @@ Known local toolchain state:
   format/type, stroke mixer depth/scissor/blend state, saved viewport and
   clear-state queries, active texture units, fallback 2D texture unbind
   targets, and stroke background copy targets.
+  Canvas stroke commit also consumes backend-owned saved viewport/clear/blend
+  state, history readback format/type, active texture units, fallback 2D
+  texture unbind targets, and layer compositing copy targets.
 - `windows-msvc-vcpkg-headless` validates manifest install/configure/build/test
   for the current headless component matrix; see DEBT-0007 for remaining app
   and platform triplet migration.