Tighten STR-016 archival record

docs/modernization/debt.md

@@ -401,7 +401,7 @@ agent or engineer to remove them without reconstructing context from chat.
   shrinking the helper API mismatch while `Canvas::draw_merge_branch_orchestration()`
   still owns the remaining branch orchestration.
 - 2026-06-13: `STR-016` completed in `b9ed78e1`. The per-layer composite block
-  moved out of `Canvas::draw_merge()`; this records the completed extraction.
+  moved out of `Canvas::draw_merge()`; archival record of the completed extraction.
 - 2026-06-15: `DEBT-0036` was narrowed again. `Canvas::draw_merge_branch_orchestration()`
   now drops the unused `draw_checkerboard` parameter from the internal branch
   wrapper, and `Canvas::draw_merge_temporary_paint_branch()` now drops the

docs/modernization/roadmap.md

@@ -3240,8 +3240,7 @@ Results:
   `draw_checkerboard`/helper-shape cleanup is archived under `DEBT-0036`.
 - `Canvas::draw_merge_branch_orchestration()` and
   `Canvas::draw_merge_temporary_paint_branch()` later kept narrowing
-  `DEBT-0036`, and this note is archival context for the completed
-  draw-merge extraction.
+  `DEBT-0036`; archival record of the completed `STR-016` draw-merge extraction.
 - Canvas main-brush, dual-brush, and stroke-pad draw paths now use the tested
   `pp_paint_renderer` stroke-feedback plan to decide whether framebuffer fetch
   supplies destination color or the legacy OpenGL path must copy the target