feat(wxpa): 配图提示词规则从 Go 硬编码迁移到 JSON 配置驱动

- 新增 spec/06-image_prompt_generation/rule.json 定义配图分布规则（500 字间隔、封面图、正文图尺寸）
- 新增 prompt_template、bracket_format 等 JSON 配置，支持中文提示词模板
- 修改 buildCoverImagePrompt/buildContentImagePrompt 使用 strings.ReplaceAll 替换 {index}/{section_summary} 占位符
- 修改 executeWeixinPublicAccountImagePromptStep 调用 buildWeixinPublicAccountImagePromptsV2
- 新增 buildWeixinPublicAccountContentWithPromptsFromJSON 包装 renderWeixinPublicAccountImagePromptFromJSON
- 前端产物 Tab 新增配图缩略图行展示

eai_agentplatform/backend-go/internal/specialists/packages/weixin_public_account/api/weixin_public_account_delivery.go

@@ -27,8 +27,8 @@ type weixinPublicAccountSection struct {
 }
 
 func executeWeixinPublicAccountImagePromptStep(workflow *weixinPublicAccountWorkflowState, article *weixinpublicaccountmodel.WeixinPublicAccountArticle, user *model.User, now time.Time) weixinPublicAccountStepExecution {
-	prompts := buildWeixinPublicAccountImagePrompts(workflow)
-	contentWithPrompts := buildWeixinPublicAccountContentWithPrompts(workflow.Shared.Content, prompts)
+	prompts := buildWeixinPublicAccountImagePromptsV2(workflow)
+	contentWithPrompts := buildWeixinPublicAccountContentWithPromptsFromJSON(workflow.Shared.Content, prompts)
 	workflow.Shared.ContentWithPrompts = contentWithPrompts
 	workflow.Shared.ImagePrompts = prompts
 
@@ -55,9 +55,9 @@ func executeWeixinPublicAccountImagePromptStep(workflow *weixinPublicAccountWork
 func executeWeixinPublicAccountImageGenerationStep(workflow *weixinPublicAccountWorkflowState, article *weixinpublicaccountmodel.WeixinPublicAccountArticle, user *model.User, now time.Time) (weixinPublicAccountStepExecution, *web.AppError) {
 	prompts := workflow.Shared.ImagePrompts
 	if len(prompts) == 0 {
-		prompts = buildWeixinPublicAccountImagePrompts(workflow)
+		prompts = buildWeixinPublicAccountImagePromptsV2(workflow)
 		workflow.Shared.ImagePrompts = prompts
-		workflow.Shared.ContentWithPrompts = buildWeixinPublicAccountContentWithPrompts(workflow.Shared.Content, prompts)
+		workflow.Shared.ContentWithPrompts = buildWeixinPublicAccountContentWithPromptsFromJSON(workflow.Shared.Content, prompts)
 	}
 	aiRoute, refs, appErr := generateWeixinPublicAccountImages(article.TaskID, workflow, prompts, user)
 	if appErr != nil {
@@ -181,6 +181,11 @@ func buildWeixinPublicAccountContentWithPrompts(content string, prompts []weixin
 	return strings.Join(blocks, "\n")
 }
 
+// buildWeixinPublicAccountContentWithPromptsFromJSON 基于 JSON 配置渲染带括号标记的正文。
+func buildWeixinPublicAccountContentWithPromptsFromJSON(content string, prompts []weixinPublicAccountImagePrompt) string {
+	return renderWeixinPublicAccountImagePromptFromJSON(content, prompts)
+}
+
 func buildWeixinPublicAccountVisualPrompt(workflow *weixinPublicAccountWorkflowState, sectionTitle, context string) string {
 	keyword := firstNonEmpty(workflow.Form.Keyword, "业务主题")
 	tone := firstNonEmpty(workflow.Form.Tone, "专业但好懂")

eai_agentplatform/backend-go/internal/specialists/packages/weixin_public_account/api/weixin_public_account_image_prompt_config.go

@@ -217,18 +217,20 @@ func buildWeixinPublicAccountImagePromptsV2(workflow *weixinPublicAccountWorkflo
 func buildCoverImagePrompt(workflow *weixinPublicAccountWorkflowState, rule *imagePromptRule) string {
 	title := firstNonEmpty(workflow.Shared.SelectedTitle, workflow.Form.Keyword, "公众号文章")
 
-	// 从 JSON 模板构建（当前回退到硬编码模板）
+	// 从 JSON 模板构建
 	template := rule.Template.Template
-	if template == "" {
-		// 回退到当前硬编码的英文模板
-		return fmt.Sprintf("realistic editorial illustration, Chinese business article cover, %s, focus on %s, %s, clean composition, natural lighting, brand-safe, no text, no watermark",
-			weixinPublicAccountBusinessDomainLabel(workflow.Form.BusinessDomain),
-			title,
-			"公众号封面主视觉",
-		)
+	if template != "" {
+		// 使用字符串替换，而非 fmt.Sprintf
+		prompt := strings.ReplaceAll(template, "{index}", "1")
+		prompt = strings.ReplaceAll(prompt, "{section_summary}", fmt.Sprintf("%s（截断至120字）", title))
+		return prompt
 	}
-
-	return fmt.Sprintf(template, 1, title, fmt.Sprintf("%s（截断至120字）", title))
+	// 回退到硬编码模板
+	return fmt.Sprintf("realistic editorial illustration, Chinese business article cover, %s, focus on %s, %s, clean composition, natural lighting, brand-safe, no text, no watermark",
+		weixinPublicAccountBusinessDomainLabel(workflow.Form.BusinessDomain),
+		title,
+		"公众号封面主视觉",
+	)
 }
 
 // buildContentImagePrompt 生成正文配图提示词。
@@ -237,16 +239,18 @@ func buildContentImagePrompt(workflow *weixinPublicAccountWorkflowState, section
 
 	// 从 JSON 模板构建
 	template := rule.Template.Template
-	if template == "" {
-		// 回退到当前硬编码的英文模板
-		return fmt.Sprintf("realistic editorial illustration, Chinese business article cover, %s, focus on %s, %s, clean composition, natural lighting, brand-safe, no text, no watermark",
-			weixinPublicAccountBusinessDomainLabel(workflow.Form.BusinessDomain),
-			firstNonEmpty(section.Title, workflow.Form.Keyword),
-			firstNonEmpty(summary, workflow.Form.Tone),
-		)
+	if template != "" {
+		// 使用字符串替换，而非 fmt.Sprintf
+		prompt := strings.ReplaceAll(template, "{index}", fmt.Sprintf("%d", index))
+		prompt = strings.ReplaceAll(prompt, "{section_summary}", summary)
+		return prompt
 	}
-
-	return fmt.Sprintf(template, index, firstNonEmpty(section.Title, workflow.Form.Keyword), summary)
+	// 回退到硬编码模板
+	return fmt.Sprintf("realistic editorial illustration, Chinese business article cover, %s, focus on %s, %s, clean composition, natural lighting, brand-safe, no text, no watermark",
+		weixinPublicAccountBusinessDomainLabel(workflow.Form.BusinessDomain),
+		firstNonEmpty(section.Title, workflow.Form.Keyword),
+		firstNonEmpty(summary, workflow.Form.Tone),
+	)
 }
 
 // countChineseWords 计算内容的中文字数。

eai_agentplatform/backend-go/internal/specialists/packages/weixin_public_account/api/weixin_public_account_workflow.go

@@ -792,7 +792,7 @@ func respondWeixinPublicAccountWorkflow(c *gin.Context, task model.TaskRecord) {
 func findWeixinPublicAccountImagePrompt(workflow weixinPublicAccountWorkflowState, imageKey string) (weixinPublicAccountImagePrompt, int, bool) {
 	prompts := workflow.Shared.ImagePrompts
 	if len(prompts) == 0 {
-		prompts = buildWeixinPublicAccountImagePrompts(&workflow)
+		prompts = buildWeixinPublicAccountImagePromptsV2(&workflow)
 		workflow.Shared.ImagePrompts = prompts
 	}
 	for idx, item := range prompts {