feat: 专员 JSON 配置体系 + 配图提示词规则重构

- 新增配图提示词 JSON 规则（image_prompt.json）：封面图 + 每 500 字按字数分布
- 新增 Go 配置加载器（weixin_public_account_image_prompt_config.go）：从嵌入的 spec 目录读取 JSON 配置
- 新增 weixin_public_account 完整 spec 目录：skill.md, workflow.json, domains.json, policy.json, validators/
- 新增 pj0012 参考文件（pj0012-wechat-image-spec.md）：配图规则 + 专员 JSON 定义体系
- 产物 Tab 添加下载按钮 + 整体导出区
- 修复前端 Markdown 渲染 bug + 步骤消息分段问题

所有专员定义向 JSON 配置迁移，以 weixin_public_account 为样板。

eai_agentplatform/frontend/src/components/chat/WeixinPublicAccountSpecialistPanel.vue

@@ -158,9 +158,9 @@
                     class="oa-btn oa-btn-tiny"
                     type="button"
                     :disabled="previewLoading"
-                    @click="openArtifactPreview(file)"
+                    @click="downloadFile(file)"
                   >
-                    预览
+                    下载
                   </button>
                 </div>
               </div>
@@ -169,6 +169,50 @@
             </template>
           </div>
         </section>
+
+        <!-- 整体导出区：所有格式一次导出 -->
+        <section class="oa-stack-section">
+          <div class="oa-stack-head">
+            <span class="oa-stack-title">整体导出</span>
+          </div>
+          <div v-if="hasTask" class="oa-export-row">
+            <button
+              class="oa-btn"
+              type="button"
+              :disabled="loading"
+              @click="download('preview_md')"
+            >
+              预览 MD
+            </button>
+            <button
+              class="oa-btn"
+              type="button"
+              :disabled="loading"
+              @click="download('preview_html')"
+            >
+              预览 HTML
+            </button>
+            <button
+              class="oa-btn"
+              type="button"
+              :disabled="loading"
+              @click="download('pagemd')"
+            >
+              分页 MD
+            </button>
+            <button
+              class="oa-btn"
+              type="button"
+              :disabled="loading"
+              @click="download('docx')"
+            >
+              Word (.docx)
+            </button>
+          </div>
+          <div v-else class="oa-empty oa-empty-inline">
+            没有可导出的内容，先运行创作流程。
+          </div>
+        </section>
       </template>
 
       <template v-else>
@@ -1085,6 +1129,40 @@ async function download(format) {
   }
 }
 
+// 从产物文件下载（HTML / MD 直接下载，图片通过 API 获取）
+async function downloadFile(file) {
+  loading.value = true
+  try {
+    let blob = null
+    let filename = file.name || 'download'
+
+    if (file.kind === 'html' && file.html) {
+      blob = new Blob([file.html], { type: 'text/html' })
+    } else if (file.kind === 'markdown' && file.text) {
+      blob = new Blob([file.text], { type: 'text/markdown' })
+    } else if (file.kind === 'image' && file.url) {
+      blob = await fetchWeixinPublicAccountGeneratedImage(file.url)
+      if (file.name) filename = file.name
+    }
+
+    if (blob) {
+      const url = URL.createObjectURL(blob)
+      const a = document.createElement('a')
+      a.href = url
+      a.download = filename
+      document.body.appendChild(a)
+      a.click()
+      document.body.removeChild(a)
+      URL.revokeObjectURL(url)
+      ElMessage.success('下载成功')
+    }
+  } catch (error) {
+    ElMessage.error(error?.message || '下载失败')
+  } finally {
+    loading.value = false
+  }
+}
+
 function exportFileName(format) {
   if (format === 'preview_html') return 'weixin-public-account-preview.html'
   if (format === 'pagemd') return 'weixin-public-account-pagemd.md'

eai_agentplatform/frontend/src/views/workbench/SmartAssistantPage.vue

@@ -474,7 +474,13 @@ function renderMarkdownBlock(block) {
   const headingMatch = trimmed.match(/^(#{1,3})\s+(.+)$/)
   if (headingMatch) {
     const level = headingMatch[1].length
-    return `<h${level}>${renderInlineMarkdown(headingMatch[2])}</h${level}>`
+    const heading = `<h${level}>${renderInlineMarkdown(headingMatch[2])}</h${level}>`
+    // If the block has more lines after the heading, render them as additional content
+    const afterHeading = trimmed.split('\n', 2)[1]
+    if (afterHeading && afterHeading.trim()) {
+      return heading + ' ' + renderMarkdownBlock(afterHeading.trim())
+    }
+    return heading
   }
 
   const lines = trimmed.split('\n')
@@ -792,7 +798,7 @@ function getWeixinPublicAccountStep(payload, stepKey) {
   return payload?.workflow?.steps?.[stepKey] || {}
 }
 
-function trimWeixinPublicAccountText(value, maxLength = 180) {
+function trimWeixinPublicAccountText(value, maxLength = 360) {
   const text = String(value || '').trim()
   if (!text) return ''
   return text.length > maxLength ? `${text.slice(0, maxLength).trim()}...` : text
@@ -876,7 +882,7 @@ function buildWeixinPublicAccountOutlineStageMessage(payload) {
       '### 3. 提纲步骤已完成',
       sections.length
         ? `本轮提纲主结构：\n${formatWeixinPublicAccountBulletList(sections)}`
-        : trimWeixinPublicAccountText(outline, 220) || '本轮提纲已生成。',
+        : trimWeixinPublicAccountText(outline, 500) || '本轮提纲已生成。',
     ].filter(Boolean).join('\n\n'),
     timestamp: new Date().toLocaleTimeString(),
   }
@@ -892,7 +898,7 @@ function buildWeixinPublicAccountContentStageMessage(payload) {
       .replace(/^>\s+.*$/gm, '')
       .replace(/\n{2,}/g, '\n')
       .trim(),
-    220,
+    500,
   )
   return {
     role: 'assistant',
@@ -910,15 +916,18 @@ function buildWeixinPublicAccountImagePromptStageMessage(payload) {
   const output = step.output || {}
   const count = Number(output.count || 0)
   const prompts = Array.isArray(output.image_prompts) ? output.image_prompts.slice(0, 4) : []
+  const lines = [
+    `已提炼 ${count} 条配图提示词。`,
+    ...(prompts.length
+      ? prompts.map((item, index) => `${index + 1}. [${item?.section || '段落配图'}] ${trimWeixinPublicAccountText(item?.prompt || '', 80)}`)
+      : []),
+  ]
   return {
     role: 'assistant',
     content: [
       '### 5. 配图提示词步骤已完成',
-      count > 0 ? `已提炼 ${count} 条配图提示词。` : '本轮未提炼出可用配图提示词。',
-      ...(prompts.length
-        ? prompts.map((item, index) => `${index + 1}. [${item?.section || '段落配图'}] ${trimWeixinPublicAccountText(item?.prompt || '', 80)}`)
-        : []),
-    ].filter(Boolean).join('\n'),
+      lines.length ? lines.join('\n') : '本轮未提炼出可用配图提示词。',
+    ].filter(Boolean).join('\n\n'),
     timestamp: new Date().toLocaleTimeString(),
   }
 }
@@ -929,15 +938,18 @@ function buildWeixinPublicAccountImageGenerationStageMessage(payload) {
   const output = step.output || {}
   const count = Number(output.count || 0)
   const refs = Array.isArray(output.image_refs) ? output.image_refs.slice(0, 4) : []
+  const lines = [
+    `已生成 ${count} 张配图。`,
+    ...(refs.length
+      ? refs.map((item, index) => `${index + 1}. [${item?.section || '段落配图'}] ${trimWeixinPublicAccountText(item?.prompt || '', 60)}`)
+      : []),
+  ]
   return {
     role: 'assistant',
     content: [
       '### 6. 图片生成步骤已完成',
-      count > 0 ? `已生成 ${count} 张配图。` : '本轮未生成图片结果。',
-      ...(refs.length
-        ? refs.map((item, index) => `${index + 1}. [${item?.section || '段落配图'}] ${trimWeixinPublicAccountText(item?.prompt || '', 60)}`)
-        : []),
-    ].filter(Boolean).join('\n'),
+      lines.length ? lines.join('\n') : '本轮未生成图片结果。',
+    ].filter(Boolean).join('\n\n'),
     timestamp: new Date().toLocaleTimeString(),
   }
 }
@@ -952,7 +964,7 @@ function buildWeixinPublicAccountPreviewStageMessage(payload) {
     content: [
       '### 7. 预览与导出步骤已完成',
       `已整合正文${imageCount ? `与 ${imageCount} 张配图` : ''}生成预览稿，可检查排版并导出。`,
-    ].filter(Boolean).join('\n'),
+    ].filter(Boolean).join('\n\n'),
     timestamp: new Date().toLocaleTimeString(),
   }
 }
@@ -967,7 +979,7 @@ function buildWeixinPublicAccountPageMarkdownStageMessage(payload) {
     content: [
       '### 8. 分页 MD 步骤已完成',
       count > 0 ? `已按段落结构生成 ${count} 页分页 MD。` : '分页 MD 已生成。',
-    ].filter(Boolean).join('\n'),
+    ].filter(Boolean).join('\n\n'),
     timestamp: new Date().toLocaleTimeString(),
   }
 }