refactor: 重构存储与接口适配，统一金额单位与会话管理

- 新增配置、存储、金额转换工具服务
- 按userId隔离本地缓存，替换旧设备级存储
- 统一移动端金额单位为万元，新增转换适配逻辑
- 重构认证与请求逻辑，支持真实后端会话
- 调整搜索、帮助、融资模块的模拟开关与数据适配
- 更新文档说明开发状态与配置规则

packages/content/services/search.uts

@@ -1,4 +1,4 @@
-import { API_BASE_URL, requestJson } from '@/services/api.uts'
+import { API_DEMO_ENABLED, API_BASE_URL, requestJson } from '@/services/api.uts'
 import { newsArticles, financeLessons, ContentSection } from './content.uts'
 
 export type ContentSearchResult = {
@@ -14,7 +14,7 @@ export async function searchContent(keyword: string, type: string): Promise<Cont
 	const query = keyword.trim().replace(/\s+/g, ' ')
 	const results: ContentSearchResult[] = []
 	if (query.length == 0) return results
-	if (API_BASE_URL.length > 0) {
+	if (!API_DEMO_ENABLED) {
 		const response = await requestJson('/content/search', 'GET', { keyword: query, type })
 		const items = response['items'] as UTSJSONObject[] | null
 		if (items == null) throw new Error('搜索结果加载失败，请重试')