支持规范参考图输入

为角色形象规范、UI素材规范、自定义规范面板新增参考图上传入口。

生成规范时携带参考图并自动追加参考图生成规范语义。

补充生成流程和上传流程回归测试。

更新画板角色形象生成入口设计文档。

src/components/image-editor/ImageCanvasGenerationComposerView.tsx

@@ -621,6 +621,37 @@ export function ImageCanvasGenerationComposerView({
                 ) : null}
               </>
             )}
+            {generateDialog.specType !== 'icon' ? (
+              <div className="image-canvas-editor__field-block">
+                <PlatformFieldLabel
+                  variant="form"
+                  className="image-canvas-editor__field-title"
+                >
+                  参考图
+                </PlatformFieldLabel>
+                <button
+                  type="button"
+                  className="image-canvas-editor__character-spec-ref image-canvas-editor__reference-tile image-canvas-editor__reference-tile--spec"
+                  disabled={generateDialog.status === 'generating'}
+                  onClick={() => onRequestUpload('spec-reference')}
+                >
+                  <span className="image-canvas-editor__reference-tile-visual">
+                    {generateDialog.specReference ? (
+                      <img
+                        src={generateDialog.specReference.src}
+                        alt=""
+                        aria-hidden="true"
+                      />
+                    ) : (
+                      <ImagePlus className="h-4 w-4" aria-hidden="true" />
+                    )}
+                  </span>
+                  <span className="image-canvas-editor__reference-tile-copy">
+                    {generateDialog.specReference?.label ?? '添加参考图'}
+                  </span>
+                </button>
+              </div>
+            ) : null}
           </div>
           {generateDialog.status === 'failed' ? (
             <PlatformStatusMessage