修复 UI 文本字体引用校验

按 FontSource::Bound 显式校验字体素材引用

保留系统字体不参与项目字体资产校验

apps/ai-game-creator-shell/src-tauri/src/ui_editor/persistence.rs

@@ -1,4 +1,5 @@
 use crate::ui_editor::component::Component;
+use crate::ui_editor::component::text::FontSource;
 use crate::ui_editor::layout::node::Node;
 use crate::ui_editor::state::State;
 use crate::*;
@@ -543,12 +544,10 @@ fn validate_node(
                 }
             }
             Component::Text(text) => {
-                if text
-                    .font
-                    .as_ref()
-                    .is_some_and(|id| !state.font_assets.contains_key(id))
-                {
-                    return Err("Text 组件引用了不存在的字体素材".to_string());
+                if let FontSource::Bound(id) = &text.font {
+                    if !state.font_assets.contains_key(id) {
+                        return Err("Text 组件引用了不存在的字体素材".to_string());
+                    }
                 }
             }
         }