Extract dual stroke tip dispatch overload

docs/modernization/debt.md

@@ -18,6 +18,10 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: `LATER-003` was narrowed again. `Canvas::stroke_draw()` now
+  routes dual-brush tip dispatch through retained helper overloads, so the
+  face-index callback wiring is no longer built inline in the dual-pass
+  branch.
 - 2026-06-13: `LATER-003` was narrowed again. `Canvas::stroke_draw()` now
   routes dual-brush tip dispatch through retained helper overloads, so the
   face-index callback wiring is no longer built inline in the dual-pass

tests/paint_renderer/stroke_execution_tests.cpp

@@ -316,7 +316,7 @@ void retained_stroke_brush_tip_texture_dispatch_helper_builds_expected_face_wiri
         [&](int slot) { events.emplace_back("activate:" + std::to_string(slot)); },
         [&](int face_index) { events.emplace_back("bind:" + std::to_string(face_index)); },
         [&](int face_index) { events.emplace_back("unbind:" + std::to_string(face_index)); },
-        2);
+        3);
 
     dispatch.activate_texture_unit(0);
     dispatch.bind_brush_tip();
@@ -324,8 +324,8 @@ void retained_stroke_brush_tip_texture_dispatch_helper_builds_expected_face_wiri
 
     const std::vector<std::string> expected_events {
         "activate:0",
-        "bind:2",
-        "unbind:2",
+        "bind:3",
+        "unbind:3",
     };
     PP_EXPECT(h, events == expected_events);
 }