更新组件绑定验证逻辑以支持已有独立素材验证

- 调整验证逻辑以支持引用项目中已存在的素材，同时拒绝不存在的素材
- 补充相关测试，验证未知素材与跨批次素材引用行为

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

@@ -107,7 +107,7 @@ fn collect_editable_nodes<'a>(node: &'a Node, output: &mut Vec<EditableNodeConte
 fn validate_and_materialize(
     changes: Vec<BindingChangeDraft>,
     editable_ids: &HashSet<NodeId>,
-    batch_sprite_ids: &HashSet<SpriteAssetId>,
+    known_sprite_ids: &HashSet<SpriteAssetId>,
 ) -> Result<BindingDTO, String> {
     let mut changed_ids = HashSet::new();
     let mut materialized = Vec::with_capacity(changes.len());
@@ -126,9 +126,9 @@ fn validate_and_materialize(
                 if image
                     .target_graphic
                     .as_ref()
-                    .is_some_and(|id| !batch_sprite_ids.contains(id))
+                    .is_some_and(|id| !known_sprite_ids.contains(id))
                 {
-                    return Err("组件绑定引用了不属于当前批次的独立素材".to_string());
+                    return Err("组件绑定引用了不存在的独立素材".to_string());
                 }
             }
         }
@@ -258,7 +258,8 @@ pub(crate) async fn bind_components_impl(
         .ok_or_else(|| "LLM 未返回 bind_ui_components 工具调用".to_string())?;
     let parsed = serde_json::from_str::<BindingResponse>(&call.arguments)
         .map_err(|error| format!("组件绑定工具参数无效：{error}"))?;
-    let result = validate_and_materialize(parsed.changes, &editable_ids, &batch_sprite_ids)?;
+    let known_sprite_ids = state.sprite_assets.keys().cloned().collect::<HashSet<_>>();
+    let result = validate_and_materialize(parsed.changes, &editable_ids, &known_sprite_ids)?;
     eprintln!(
         "ui_binding.completed ui_images={} sprites={} editable_nodes={} changes={}",
         state.ui_design_images.len(),
@@ -280,21 +281,27 @@ mod tests {
     }
 
     #[test]
-    fn materialization_rejects_unapproved_node_and_foreign_sprite() {
+    fn materialization_rejects_unapproved_node_and_unknown_sprite() {
         let editable = HashSet::from([id("editable")]);
-        let sprites = HashSet::from([SpriteAssetId::new("sprite").expect("valid sprite")]);
+        let known = HashSet::from([
+            SpriteAssetId::new("sprite").expect("valid sprite"),
+            SpriteAssetId::new("other-batch-sprite").expect("valid sprite"),
+        ]);
         let unapproved = BindingChangeDraft {
             node_id: id("other"),
             components: Vec::new(),
             components_status: DraftStatus::NoProblem,
         };
-        assert!(validate_and_materialize(vec![unapproved], &editable, &sprites).is_err());
+        assert!(validate_and_materialize(vec![unapproved], &editable, &known).is_err());
 
-        let foreign = BindingChangeDraft {
+        // References to sprites from another batch are allowed once they exist in the project.
+        let other_batch = BindingChangeDraft {
             node_id: id("editable"),
             components: vec![Component::Image(
                 crate::ui_editor::component::image::ImageComponent {
-                    target_graphic: Some(SpriteAssetId::new("foreign").expect("valid sprite")),
+                    target_graphic: Some(
+                        SpriteAssetId::new("other-batch-sprite").expect("valid sprite"),
+                    ),
                     image_type: crate::ui_editor::component::image::ImageType::Simple {
                         preserve_aspect: false,
                     },
@@ -302,7 +309,22 @@ mod tests {
             )],
             components_status: DraftStatus::NoProblem,
         };
-        assert!(validate_and_materialize(vec![foreign], &editable, &sprites).is_err());
+        assert!(validate_and_materialize(vec![other_batch], &editable, &known).is_ok());
+
+        // References to sprites that do not exist in the project at all are still rejected.
+        let unknown = BindingChangeDraft {
+            node_id: id("editable"),
+            components: vec![Component::Image(
+                crate::ui_editor::component::image::ImageComponent {
+                    target_graphic: Some(SpriteAssetId::new("unknown").expect("valid sprite")),
+                    image_type: crate::ui_editor::component::image::ImageType::Simple {
+                        preserve_aspect: false,
+                    },
+                },
+            )],
+            components_status: DraftStatus::NoProblem,
+        };
+        assert!(validate_and_materialize(vec![unknown], &editable, &known).is_err());
     }
 
     #[test]