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/tests/assistant-suggested-action-prefill.test.mjs

@@ -0,0 +1,43 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+
+import {
+  mergeComposerPrefill,
+  resolveSuggestedActionPrefill
+} from '../src/utils/assistantSuggestedActionPrefill.js'
+
+test('suggested action prefill uses backend prompt payload', () => {
+  assert.equal(
+    resolveSuggestedActionPrefill({
+      action_type: 'prefill_composer',
+      payload: {
+        application_field: 'time',
+        prompt_prefill: '申请时间段：'
+      }
+    }),
+    '申请时间段：'
+  )
+})
+
+test('suggested action prefill falls back to application field templates', () => {
+  assert.equal(
+    resolveSuggestedActionPrefill({
+      action_type: 'prefill_composer',
+      payload: { application_field: 'amount' }
+    }),
+    '预计总费用：'
+  )
+  assert.equal(
+    resolveSuggestedActionPrefill({
+      action_type: 'ask_clarification',
+      payload: { application_field: 'amount' }
+    }),
+    ''
+  )
+})
+
+test('composer prefill appends to existing draft without duplication', () => {
+  assert.equal(mergeComposerPrefill('', '事由：'), '事由：')
+  assert.equal(mergeComposerPrefill('地点：上海', '事由：'), '地点：上海\n事由：')
+  assert.equal(mergeComposerPrefill('地点：上海\n事由：', '事由：'), '地点：上海\n事由：')
+})