Route canvas input policy through platform services

src/platform_legacy/legacy_platform_services.cpp

@@ -499,6 +499,25 @@ public:
 #endif
     }
 
+    [[nodiscard]] bool draws_canvas_tip_for_pointer(
+        bool is_mouse,
+        bool is_stylus,
+        bool is_left_button_release) override
+    {
+#if defined(__IOS__)
+        (void)is_stylus;
+        return is_mouse && !is_left_button_release;
+#else
+        (void)is_left_button_release;
+        return is_mouse || is_stylus;
+#endif
+    }
+
+    [[nodiscard]] float adjust_canvas_input_pressure(float pressure) override
+    {
+        return pressure;
+    }
+
     [[nodiscard]] pp::platform::PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,