数据分析ui补充完善，接入数据库

services/analytics/dashboardService.uts

@@ -12,8 +12,19 @@ function safeNumber(v: any): number {
   return isFinite(n) ? n : 0
 }
 
-export async function fetchDashboardTrend(period: string): Promise<TrendData> {
-  const { startIso, endIso } = computeDateRange(period)
+export async function fetchDashboardTrend(period: string, range?: { start: string; end: string } | null): Promise<TrendData> {
+  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 p_start_date = toDateOnly(startIso)
   const p_end_date = toDateOnly(endIso)