feat: 新增预算助手报告组件并优化报销交互细节

新增预算助手报告视图模型和组件，优化报销洞察面板和消息项
样式细节，完善预算中心页面布局和文档中心视图，增强报销创
建会话管理和提交编排器，调整 Vite 构建配置，补充单元测试。

web/src/views/scripts/useTravelReimbursementSessionState.js

@@ -14,6 +14,7 @@ import {
   ASSISTANT_SESSION_TYPES,
   filterAssistantSessionTypes,
   SESSION_TYPE_APPLICATION,
+  SESSION_TYPE_BUDGET,
   SESSION_TYPE_EXPENSE,
   buildInitialInsightFromConversation,
   buildWelcomeInsight,
@@ -64,6 +65,9 @@ export function useTravelReimbursementSessionState({
   }
 
   function resolveDefaultSessionTypeFromEntry() {
+    if (props.entrySource === 'budget') {
+      return SESSION_TYPE_BUDGET
+    }
     return props.entrySource === 'application' ? SESSION_TYPE_APPLICATION : SESSION_TYPE_EXPENSE
   }
 
@@ -197,6 +201,7 @@ export function useTravelReimbursementSessionState({
     : buildEmptySessionState(initialSessionType)
   const canRestorePersistedInitialState =
     shouldPersistLocalSnapshot
+      && props.entrySource !== 'budget'
       && !String(props.initialPrompt || '').trim()
       && !props.initialFiles.length
   const persistedInitialSnapshot = readAssistantSessionSnapshot(resolveCurrentUserId(), initialSessionType)