Align draw merge default comment

docs/modernization/roadmap.md

@@ -80,6 +80,9 @@ families debt-tracked.
 The stale `make_canvas_draw_merge_branch_dispatch(...)` forward declaration in
 `src/canvas.cpp` now matches the existing 7-argument implementation, shrinking
 the remaining draw-merge helper API mismatch while `STR-016` stays blocked.
+The remaining `Canvas::draw_merge()` inline-default comment in `src/canvas.cpp`
+now matches the header's `SIXPLETTE(true)` default, so the draw-merge mismatch
+is comment-only and aligned while `STR-016` stays blocked.
 The cloud browser dialog now also opens through that seam from
 `src/legacy_cloud_services.cpp`, so the remaining cloud modernization debt is
 now concentrated in retained background worker threads, transfer helpers,