改为行引用保存画布参考图元数据

生成输入参考图只保存 refType/refId 行引用
生成器布局快照只保存参考图行指针并在加载时恢复临时源
上传参考图优先创建项目资源行并回写 resourceId
元数据弹窗改为展示参考图行引用信息
更新图片画布技术文档和项目决策记录

src/index.css

@@ -7405,7 +7405,6 @@ button.image-canvas-editor__reference-chip:disabled {
 
 .image-canvas-editor__metadata-reference-card {
   display: grid;
-  grid-template-columns: 2.4rem minmax(0, 1fr);
   align-items: center;
   gap: 0.5rem;
   width: 100%;
@@ -7415,19 +7414,18 @@ button.image-canvas-editor__reference-chip:disabled {
   padding: 0.38rem;
 }
 
-.image-canvas-editor__metadata-reference-card img {
-  width: 2.4rem;
-  height: 2.4rem;
-  border-radius: 0.48rem;
-  object-fit: cover;
-}
-
 .image-canvas-editor__metadata-reference-copy {
   display: grid;
   min-width: 0;
   gap: 0.12rem;
 }
 
+.image-canvas-editor__metadata-reference-id {
+  color: #64748b;
+  font-size: 0.72rem;
+  overflow-wrap: anywhere;
+}
+
 @media (max-width: 760px) {
   .image-canvas-editor {
     flex-direction: column;