Extract dual brush tip dispatch

docs/modernization/debt.md

@@ -537,6 +537,10 @@ agent or engineer to remove them without reconstructing context from chat.
   sampler dispatch now has regression coverage through
   `make_legacy_canvas_stroke_live_pass_sampler_dispatch(...)`; the live path
   still owns the concrete sampler objects and binding state.
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw()` dual-pass
+  brush-tip dispatch now uses a retained helper object, with regression
+  coverage proving the helper order; the live path still owns the concrete
+  brush-tip texture object and dual-pass branch wiring.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::draw_merge` checkerboard
   background shader setup and final merged-texture redraw setup now route
   through `legacy_canvas_draw_merge_services.h`. The retained Canvas path still