feat(imitation): add article imitation create flow

Introduce 仿写创作: new list and create views, backend imitation service
and prompt templates, worker task routing for imitation jobs, and one-click
rewrite triggers from question citation sources. Surface source article
URL/title on article list/detail, and restrict failed articles to delete-only.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/views/WorkspaceView.vue

@@ -190,7 +190,7 @@ async function openEditor(article: RecentArticle): Promise<void> {
   try {
     const detail = await articlesApi.detail(article.id);
 
-    if (detail.generate_status !== "completed" && detail.source_type === "template" && detail.template_id) {
+    if (detail.generate_status === "draft" && detail.source_type === "template" && detail.template_id) {
       await router.push({
         name: "article-wizard",
         query: {