fix: 优化报销创建页面样式与洞察面板交互

修复侧边栏和审计视图样式细节，完善差旅报销洞察面板和消息
组件布局，优化报销创建页面会话管理和流程状态持久化，增强
申请预览工具函数和导航图标，补充单元测试。

web/src/views/scripts/travelReimbursementConversationModel.js

@@ -2,6 +2,7 @@ import { buildSuggestedActionKey } from '../../utils/suggestedActionKey.js'
 import { normalizeExpenseQueryPayload } from './travelReimbursementExpenseQueryModel.js'
 import { buildAgentInsight, buildReviewFilePreviewsFromReviewPayload } from './travelReimbursementAttachmentModel.js'
 import { resolveExpenseTypeLabel } from './travelReimbursementReviewModel.js'
+import { isBudgetMonitorUser, isExecutiveUser } from '../../utils/accessControl.js'
 import {
   GUIDED_ACTION_OPEN_TRAVEL_CALCULATOR,
   GUIDED_ACTION_START_APPLICATION,
@@ -13,12 +14,14 @@ export const SESSION_TYPE_EXPENSE = 'expense'
 export const SESSION_TYPE_APPLICATION = 'application'
 export const SESSION_TYPE_APPROVAL = 'approval'
 export const SESSION_TYPE_KNOWLEDGE = 'knowledge'
+export const SESSION_TYPE_BUDGET = 'budget'
 
 export const ASSISTANT_SESSION_TYPES = [
   SESSION_TYPE_APPLICATION,
   SESSION_TYPE_EXPENSE,
   SESSION_TYPE_APPROVAL,
-  SESSION_TYPE_KNOWLEDGE
+  SESSION_TYPE_KNOWLEDGE,
+  SESSION_TYPE_BUDGET
 ]
 
 export const ASSISTANT_SESSION_MODE_OPTIONS = [
@@ -45,9 +48,39 @@ export const ASSISTANT_SESSION_MODE_OPTIONS = [
     label: '财务知识助手',
     icon: 'mdi mdi-book-open-page-variant-outline',
     description: '只处理财务制度、标准规则、票据要求和政策解释'
+  },
+  {
+    key: SESSION_TYPE_BUDGET,
+    label: '预算编制助手',
+    icon: 'mdi mdi-calculator-variant-outline',
+    description: '帮助你进行预算编制与预算相关问题的整理'
   }
 ]
 
+export function canUseBudgetAssistantSession(user = null) {
+  return Boolean(isBudgetMonitorUser(user) || isExecutiveUser(user))
+}
+
+function canUseAssistantSessionType(sessionType, user = null) {
+  const normalized = String(sessionType || '').trim()
+  if (normalized === SESSION_TYPE_BUDGET) {
+    return canUseBudgetAssistantSession(user)
+  }
+  return true
+}
+
+export function filterAssistantSessionModes(sessionModes = [], user = null) {
+  return Array.isArray(sessionModes)
+    ? sessionModes.filter((mode) => canUseAssistantSessionType(mode?.key, user))
+    : []
+}
+
+export function filterAssistantSessionTypes(sessionTypes = [], user = null) {
+  return Array.isArray(sessionTypes)
+    ? sessionTypes.filter((sessionType) => canUseAssistantSessionType(String(sessionType || '').trim(), user))
+    : []
+}
+
 export function normalizeAssistantSessionType(sessionType, fallback = SESSION_TYPE_EXPENSE) {
   const normalized = String(sessionType || '').trim()
   if (ASSISTANT_SESSION_TYPES.includes(normalized)) {