Centralize legacy canvas tool bridge

src/legacy_canvas_tool_services.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "app_core/canvas_hotkey.h"
+#include "app_core/canvas_tool_ui.h"
+#include "foundation/result.h"
+
+class App;
+class Node;
+
+namespace pp::panopainter {
+
+[[nodiscard]] pp::foundation::Status execute_legacy_canvas_tool_plan(
+    App& app,
+    const pp::app::CanvasToolPlan& plan,
+    Node* toolbar_button = nullptr);
+[[nodiscard]] pp::foundation::Status execute_legacy_canvas_input_tool_plan(
+    const pp::app::CanvasToolPlan& plan);
+[[nodiscard]] pp::foundation::Status execute_legacy_canvas_hotkey_plan(
+    const pp::app::CanvasHotkeyPlan& plan);
+
+} // namespace pp::panopainter