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/assets/styles/views/travel-reimbursement-create-view-part3.css

@@ -200,7 +200,7 @@
 }
 
 .review-message-block {
-  margin-top: 8px;
+  margin-top: 10px;
 }
 
 .review-summary {
@@ -208,12 +208,12 @@
   color: #1f2937;
   font-size: var(--wb-fs-bubble);
   line-height: 1.58;
-  white-space: pre-line;
+  white-space: normal;
 }
 
 .review-plain-followup {
   display: grid;
-  gap: 7px;
+  gap: 10px;
   padding: 0;
   color: #334155;
   font-size: var(--wb-fs-bubble);
@@ -225,13 +225,31 @@
 }
 
 .review-plain-lead {
-  color: #334155;
+  margin: 0 0 2px;
+  padding-left: 8px;
+  border-left: 3px solid #2563eb;
+  color: #0f172a;
+  font-size: max(13px, calc(var(--wb-fs-bubble) + 1px));
+  font-weight: 820;
+  line-height: 1.42;
+  letter-spacing: 0;
+}
+
+.review-plain-lead.danger {
+  border-left-color: #dc2626;
+  color: #b91c1c;
+}
+
+.review-plain-summary {
+  margin: 0;
+  color: #64748b;
+  line-height: 1.62;
 }
 
 .review-plain-list {
   display: grid;
-  gap: 4px;
-  margin: 0;
+  gap: 7px;
+  margin: 2px 0 0;
   padding: 0 0 0 18px;
 }
 
@@ -247,11 +265,14 @@
 }
 
 .review-plain-note {
+  margin-top: 2px;
   color: #64748b;
 }
 
 .review-inline-save-copy {
+  margin-top: 46px !important;
   color: #475569;
+  line-height: 1.62;
 }
 
 .review-inline-draft-link {