数据库文档编写，开发规范文档，数据库接入

services/analytics/marketTrendsService.uts

@@ -11,8 +11,19 @@ export type MarketTrendsData = {
   endIso: string
 }
 
-export async function fetchMarketTrends(period: string): Promise<MarketTrendsData> {
-  const { startIso, endIso } = computeDateRange(period)
+export async function fetchMarketTrends(period: string, range?: { start: string; end: string } | null): Promise<MarketTrendsData> {
+  let startIso: string;
+  let endIso: string;
+
+  if (range != null && range.start && range.end) {
+    startIso = range.start;
+    endIso = range.end;
+  } else {
+    const computedRange = computeDateRange(period)
+    startIso = computedRange.startIso
+    endIso = computedRange.endIso
+  }
+
   const startDate = toDateOnly(startIso)
   const endDate = toDateOnly(endIso)