Tighten STR-016 archival wording

docs/modernization/debt.md

@@ -401,9 +401,8 @@ 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()`, and the helper-shape cleanup that had
-  been keeping the extraction blocked now reads as completed historical
-  context.
+  moved out of `Canvas::draw_merge()`, and the helper-shape cleanup is
+  recorded here as completed historical context.
 - 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

@@ -3238,11 +3238,11 @@ Results:
 - `STR-016` completed on 2026-06-13 in `b9ed78e1`; the per-layer composite
   block moved out of `Canvas::draw_merge()`, and the follow-on
   `draw_checkerboard`/helper-shape cleanup is archived as `DEBT-0036`
-  reduction.
+  reduction only.
 - `Canvas::draw_merge_branch_orchestration()` and
   `Canvas::draw_merge_temporary_paint_branch()` later kept narrowing
-  `DEBT-0036`, but the draw-merge extraction itself is no longer blocked by
-  the helper API shape mismatch.
+  `DEBT-0036`, and this note remains archival context for the completed
+  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