Share retained stroke temporary composite helper

docs/modernization/debt.md

@@ -38,6 +38,11 @@ agent or engineer to remove them without reconstructing context from chat.
   through `execute_legacy_canvas_stroke_face_sample_polygon(...)`; the
   retained sample executor owns the face-aware dispatch contract while
   `Canvas` keeps only concrete GL object callbacks.
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::draw_merge()` non-erase
+  live temporary-stroke composite now routes setup, sampler bind, texture
+  bind, draw, and texture unbind ordering through
+  `execute_legacy_canvas_stroke_temporary_composite(...)`; erase-path and
+  broader final composite ownership remain retained in `Canvas`.
 - 2026-06-13: DEBT-0036 was narrowed again. `NodeStrokePreview::stroke_draw_mix()`
   now routes mixer framebuffer bind/unbind, viewport/scissor/blend state,
   texture-slot binding, and final plane draw through one local helper;