feat: 支持会商 Markdown 产物提交到任务过程，并补充 Angular 对接文档

8BF/会商工作区可将 Markdown 产物一键提交到任务过程报告，后端记录提交状态以便跨用户与刷新后保持已提交；同时为 Angular 智能体对话对接文档补上前后端参考代码索引。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend-web/src/components/workspace/artifacts/artifact-file-detail.tsx

@@ -154,6 +154,7 @@ export function ArtifactFileDetail({
   hideFileName = false,
   onDownloadClick,
   toolbarActions,
+  headerLeadingAction,
   researchSessionId,
 }: {
   className?: string;
@@ -189,6 +190,8 @@ export function ArtifactFileDetail({
    * 放置全文改写入口，避免再在沙箱内容区叠一个文字按钮。
    */
   toolbarActions?: ReactNode;
+  /** Replaces the left file-type badge for an embedded workspace action. */
+  headerLeadingAction?: ReactNode;
 }) {
   const { t } = useI18n();
   const { artifacts, setOpen, select } = useArtifacts();
@@ -1203,9 +1206,11 @@ export function ArtifactFileDetail({
       <ArtifactHeader className="flex flex-wrap items-center gap-3 px-4 py-3">
         <div className="flex min-w-0 items-center gap-2">
           <div className="bg-muted/65 inline-flex min-w-0 items-center rounded-full border border-black/6 p-1 shadow-sm dark:border-white/8">
-            <span className="bg-background text-muted-foreground inline-flex h-7 shrink-0 items-center rounded-full border border-black/6 px-2.5 text-[10px] font-semibold tracking-[0.16em] dark:border-white/8">
-              {fileTypeLabel}
-            </span>
+            {headerLeadingAction ?? (
+              <span className="bg-background text-muted-foreground inline-flex h-7 shrink-0 items-center rounded-full border border-black/6 px-2.5 text-[10px] font-semibold tracking-[0.16em] dark:border-white/8">
+                {fileTypeLabel}
+              </span>
+            )}
             {!hideFileName && (
             <ArtifactTitle className="min-w-0">
               {/* markdown：隐藏文件名（仅留 MD 徽标），把横向空间让给工具栏，避免窄面板下