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/tests/expense-application-fast-preview.test.mjs

@@ -180,8 +180,8 @@ test('application preview keeps rule fallback distinct from model reviewed resul
 
   assert.equal(fallbackPreview.modelReviewStatus, 'fallback')
   assert.match(message, /规则兜底/)
-  assert.match(footer, /规则兜底/)
-  assert.doesNotMatch(footer, /#application-submit/)
+  assert.match(footer, /请确认上述的信息是否填写正确/)
+  assert.match(footer, /#application-submit/)
 })
 
 test('application preview with missing budget stays in chat and asks for补充信息', () => {
@@ -280,6 +280,8 @@ test('application session shows intent flow, persists preview, and supports inli
   assert.match(messageItemStyles, /\.application-preview-row \{[\s\S]*grid-template-columns: 108px minmax\(0, 1fr\);/)
   assert.match(messageItemStyles, /\.application-preview-text \{[\s\S]*overflow-wrap: anywhere;/)
   assert.match(messageItemStyles, /\.application-preview-select \{[\s\S]*width: 100%;/)
+  assert.match(messageItemStyles, /\.application-preview-footer \{[\s\S]*margin-top: 48px;/)
+  assert.match(messageItemStyles, /\.message-answer-markdown :deep\(\.markdown-action-link\) \{[\s\S]*text-decoration: underline;/)
   assert.match(messageItemStyles, /\.application-preview-footer-missing \{[\s\S]*margin-top: 48px;[\s\S]*background: transparent;/)
   assert.match(messageItemStyles, /\.application-preview-missing-chip \{[\s\S]*background: rgba\(var\(--theme-primary-rgb/)
 })