Extract layer rename dialog and brush preset registry shells

docs/modernization/roadmap.md

@@ -84,7 +84,7 @@ Current hotspot files:
 - `src/canvas_modes.cpp`: 176 lines
 - `src/node.cpp`: 222 lines
 - `src/main.cpp`: 130 lines
-- `src/node_panel_brush.cpp`: 186 lines
+- `src/node_panel_brush.cpp`: 182 lines
 - `src/node_stroke_preview.cpp`: 192 lines
 - `src/node_canvas.cpp`: 69 lines
 - `src/app.cpp`: 105 lines
@@ -370,8 +370,10 @@ Current architecture mismatches that must be treated as real blockers:
   `NodePanelBrushPreset` registration/lifecycle pocket now also routes through
   the preset-list helper registry instead of a node-local static vector,
   which removes the remaining live preset-panel ownership glue from
-  `src/node_panel_brush.cpp`. The broader preset workflow pocket still remains,
-  while `NodeCanvas::handle_event()`
+  `src/node_panel_brush.cpp`, and preset-restore notification visibility now
+  also stays with `src/legacy_brush_preset_services.*` instead of the node
+  wrapper. The broader preset workflow pocket still remains, while
+  `NodeCanvas::handle_event()`
   now also routes
   through `execute_node_canvas_handle_event(...)`, which trims another coherent
   input-routing block from `src/node_canvas.cpp` even though the file is still