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>

server/internal/tenant/transport/article_handler.go

@@ -22,6 +22,7 @@ type ArticleHandler struct {
 	svc               *app.ArticleService
 	selectionOptimize *app.ArticleSelectionOptimizeService
 	promptGenerateSvc *app.PromptRuleGenerationService
+	imitationSvc      *app.ArticleImitationService
 	streams           *stream.GenerationHub
 	streamEnabled     bool
 	assets            *AssetHandler
@@ -57,6 +58,15 @@ func NewArticleHandler(a *bootstrap.App) *ArticleHandler {
 			a.Config.Generation,
 			a.Config.LLM.MaxOutputTokens,
 		).WithCache(a.Cache),
+		imitationSvc: app.NewArticleImitationService(
+			a.DB,
+			a.LLM,
+			a.RabbitMQ,
+			knowledgeSvc,
+			a.GenerationStreams,
+			a.Config.Generation,
+			a.Config.LLM.MaxOutputTokens,
+		).WithCache(a.Cache),
 		streams:       a.GenerationStreams,
 		streamEnabled: a.Config.Generation.StreamEnabled,
 		assets:        NewAssetHandler(a),
@@ -162,6 +172,22 @@ func (h *ArticleHandler) GenerateFromRule(c *gin.Context) {
 	response.SuccessWithStatus(c, http.StatusCreated, data)
 }
 
+func (h *ArticleHandler) GenerateImitation(c *gin.Context) {
+	var req app.GenerateImitationRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.Error(c, response.ErrBadRequest(40001, "invalid_params", err.Error()))
+		return
+	}
+
+	data, err := h.imitationSvc.Generate(c.Request.Context(), req)
+	if err != nil {
+		response.Error(c, err)
+		return
+	}
+
+	response.SuccessWithStatus(c, http.StatusCreated, data)
+}
+
 func (h *ArticleHandler) Create(c *gin.Context) {
 	var req app.CreateArticleRequest
 	if err := c.ShouldBindJSON(&req); err != nil {