Route stroke preview mixer composite through service

docs/modernization/debt.md

@@ -18,6 +18,11 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: DEBT-0036 was narrowed again. `NodeStrokePreview::stroke_draw_mix`
+  now reuses `legacy_canvas_stroke_composite_services.h` for mixer-pass
+  `kShader::CompDraw` binding and composite/pattern/dual uniform writes.
+  Mixer framebuffer, scissor/capability state, texture binding, and draw/copy
+  ordering remain retained legacy execution.
 - 2026-06-13: DEBT-0036 was narrowed again. `NodeStrokePreview` final preview
   background capture, composite input binding/draw, and preview texture copy now
   route through `legacy_canvas_stroke_preview_services.h`, with semantic preview

docs/modernization/roadmap.md

@@ -1362,7 +1362,8 @@ ordering, RTT/texture binding, history mutation, and final dirty state storage.
 `NodeStrokePreview` also now consumes a tested preview composite sequence plan
 for mixer intent, and retained preview background capture, composite input
 binding/draw, and preview texture copy are centralized behind
-`legacy_canvas_stroke_preview_services.h`.
+`legacy_canvas_stroke_preview_services.h`. Preview mixer-pass `CompDraw` setup
+now also reuses `legacy_canvas_stroke_composite_services.h`.
 It also owns renderer API texture-format to
 OpenGL internal/pixel/component token mapping, including depth-stencil formats,
 for future backend texture objects. `Texture2D` 2D texture binding, upload,