feat: 完善文档中心与报销申请交互及侧边栏重构

后端优化编排器报销查询和本体检测精度，增强报销单草稿保
存和附件回填逻辑，前端重构侧边栏组件支持折叠和图标导
航，完善文档中心状态筛选和详情提示，报销创建和审批详情
页优化会话管理和费用明细交互，新增助手应用服务和预设动
作工具函数，补充单元测试覆盖。

web/src/utils/assistantSuggestedActionPrefill.js

@@ -0,0 +1,46 @@
+const APPLICATION_FIELD_PREFILLS = {
+  time: '申请时间段：',
+  time_range: '申请时间段：',
+  location: '地点：',
+  reason: '事由：',
+  days: '天数：',
+  transport_mode: '出行方式：',
+  amount: '预计总费用：'
+}
+
+export function resolveSuggestedActionPrefill(action = {}) {
+  const payload = action?.payload && typeof action.payload === 'object' ? action.payload : {}
+  const explicitPrefill = String(
+    payload.prompt_prefill
+      || payload.input_prefill
+      || payload.prefill_text
+      || ''
+  ).trim()
+  if (explicitPrefill) {
+    return explicitPrefill
+  }
+
+  const actionType = String(action?.action_type || '').trim()
+  if (actionType !== 'prefill_composer') {
+    return ''
+  }
+
+  const applicationField = String(payload.application_field || '').trim()
+  return APPLICATION_FIELD_PREFILLS[applicationField] || ''
+}
+
+export function mergeComposerPrefill(currentDraft = '', prefill = '') {
+  const normalizedPrefill = String(prefill || '').trim()
+  if (!normalizedPrefill) {
+    return String(currentDraft || '')
+  }
+
+  const current = String(currentDraft || '')
+  if (!current.trim()) {
+    return normalizedPrefill
+  }
+  if (current.includes(normalizedPrefill)) {
+    return current
+  }
+  return `${current.trimEnd()}\n${normalizedPrefill}`
+}