Align draw merge default comment

docs/modernization/debt.md

@@ -413,6 +413,10 @@ agent or engineer to remove them without reconstructing context from chat.
   `make_canvas_draw_merge_branch_dispatch(...)` forward declaration in
   `src/canvas.cpp` now matches the 7-argument implementation, shrinking the
   remaining draw-merge helper API mismatch while `STR-016` stays blocked.
+- 2026-06-15: `DEBT-0036` was narrowed again. 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.
 - 2026-06-14: `DEBT-0036` was narrowed again. `Canvas::draw_merge_branch_orchestration()`
   now routes the temporary erase, temporary paint, texture, and blend dispatch
   bodies through retained helpers inside `execute_canvas_draw_merge_branch_body(...)`;