feat: 重构报销单服务并完善前端提交与审核交互

重构 expense_claims 服务模块结构并优化差旅票据审核逻辑，
增强用户代理服务的票据类型识别，前端报销创建页面拆分为
附件模型和会话模型模块，重构提交编排器和草稿关联确认流
程，更新知识库索引，补充单元测试。

web/src/views/TravelReimbursementCreateView.vue

@@ -88,9 +88,10 @@
                       <time>{{ message.time }}</time>
                     </header>
                     <div
-                      v-if="message.text && message.role === 'assistant' && message.reviewPayload"
+                      v-if="message.text && message.role === 'assistant' && message.reviewPayload && buildReviewMainMessageText(message)"
                       class="review-summary message-answer-content message-answer-markdown"
-                      v-html="renderMarkdown(message.text)"
+                      v-html="renderMarkdown(buildReviewMainMessageText(message))"
+                      @click="handleAssistantMarkdownClick($event, message)"
                     ></div>
 
                     <div
@@ -103,6 +104,7 @@
                       v-else-if="message.text && message.role === 'assistant'"
                       class="message-answer-content message-answer-markdown"
                       v-html="renderMarkdown(message.text)"
+                      @click="handleAssistantMarkdownClick($event, message)"
                     ></div>
 
                     <div
@@ -298,7 +300,15 @@
                           v-for="followup in [buildReviewPlainFollowupCopy(message.reviewPayload)]"
                           :key="`${message.id}-review-followup`"
                         >
-                          <p class="review-plain-lead">{{ followup.lead }}</p>
+                          <h3
+                            class="review-plain-lead"
+                            :class="{ danger: followup.tone === 'danger' }"
+                          >
+                            {{ followup.lead }}
+                          </h3>
+                          <p v-if="followup.summary" class="review-plain-summary">
+                            {{ followup.summary }}
+                          </p>
                           <ul v-if="followup.items.length" class="review-plain-list">
                             <li
                               v-for="item in followup.items"