fix: refactor time range to single source of truth with correct dates

- Default range changed from 30d to 7d
- Presets (today/7d/30d) now directly set customStart/customEnd dates,
  eliminating duplicate getTimeRange() calculation
- "All" preset fetches actual data boundaries from /api/date-range
  and backfills the custom date picker
- Clicking "custom" opens popover without triggering data refresh;
  only confirm applies changes
- SQL trend dates cast to ::text to avoid pg driver Date timezone offset
- Fix created_at filter from < to <= for end timestamp

lib/queries.ts

@@ -6,6 +6,18 @@ const REAL_MODEL = `COALESCE(
        THEN other::jsonb->>'upstream_model_name' END,
   model_name)`;
 
+// ── 数据时间边界 ────────────────────────────────────────────────
+
+export async function getDateRange(): Promise<{ minDate: string; maxDate: string }> {
+  const rows = await query(
+    `SELECT
+       ((MIN(to_timestamp(created_at)) AT TIME ZONE 'Asia/Shanghai')::date)::text as min_date,
+       ((MAX(to_timestamp(created_at)) AT TIME ZONE 'Asia/Shanghai')::date)::text as max_date
+     FROM logs WHERE type = 2`
+  );
+  return { minDate: rows[0]?.min_date ?? "", maxDate: rows[0]?.max_date ?? "" };
+}
+
 // 时间条件构建
 function timeWhere(
   params: (string | number | boolean | null)[],
@@ -19,7 +31,7 @@ function timeWhere(
   }
   if (endTs) {
     params.push(endTs);
-    where += ` AND created_at < $${params.length}`;
+    where += ` AND created_at <= $${params.length}`;
   }
   return where;
 }
@@ -91,8 +103,8 @@ export async function getTrends(
 
   const truncExpr =
     granularity === "day"
-      ? `(to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date`
-      : `date_trunc('${granularity}', to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date`;
+      ? `((to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date)::text`
+      : `(date_trunc('${granularity}', to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date)::text`;
 
   const rows = await query(
     `SELECT
@@ -107,7 +119,7 @@ export async function getTrends(
   );
 
   return rows.map((r) => ({
-    date: r.date instanceof Date ? r.date.toISOString().slice(0, 10) : String(r.date).slice(0, 10),
+    date: String(r.date).slice(0, 10),
     calls: Number(r.calls),
     prompt_tokens: Number(r.prompt_tokens),
     completion_tokens: Number(r.completion_tokens),