consumer模块完成90%，前端完成supabase对接

mall/services/analytics/dateRange.uts

@@ -0,0 +1,15 @@
+export type DateRange = { startIso: string; endIso: string }
+
+export function computeDateRange(period: string): DateRange {
+  const now = new Date()
+  const start = new Date(now.getTime())
+  if (period === '7d') start.setDate(start.getDate() - 7)
+  else if (period === '30d') start.setDate(start.getDate() - 30)
+  else if (period === '90d') start.setDate(start.getDate() - 90)
+  else if (period === '1y') start.setFullYear(start.getFullYear() - 1)
+  return { startIso: start.toISOString(), endIso: now.toISOString() }
+}
+
+export function toDateOnly(iso: string): string {
+  return iso.length >= 10 ? iso.substring(0, 10) : iso
+}