fix(时长): 所有时长计算排除非工作日 + 修复两处时区多算8小时

- get_wip_tasks/get_people_workload/get_people_history/product active_duration_hours/analytics 均改用 working_duration_hours
- 修复 get_wip_tasks 与 active_duration_hours 的 naive 时间误标北京时间 bug(DB实存UTC，原多算8小时)
- 每处读取 holidays 表排除配置的放假日期

backend/app/services/product_service.py

@@ -541,11 +541,14 @@ async def get_all_products(
             has_img = bool(row[3] and row[3] != "[]" and row[3] != "null")
             latest_record_map[row[0]] = (row[1], row[2], has_img, row[4])
 
-    # 🔧 当前人滞留时长：每个产品活跃任务(WIP/PENDING)最早接手时间 → 小时
+    # 🔧 当前人滞留时长：每个产品活跃任务(WIP/PENDING)最早接手时间 → 小时（排除非工作日）
     active_duration_map: dict[uuid.UUID, float] = {}
     if product_ids:
         from sqlalchemy import func as sa_func
-        from app.core.time_utils import get_beijing_time, BEIJING_TZ
+        from app.core.time_utils import get_beijing_time, to_beijing, working_duration_hours
+        from app.models.holiday import Holiday
+        hres = await db.execute(select(Holiday.day))
+        holidays = {r[0] for r in hres}
         start_stmt = (
             select(
                 Task.product_id,
@@ -563,11 +566,8 @@ async def get_all_products(
             start = row[1]
             if start is None:
                 continue
-            if start.tzinfo is None:
-                start = start.replace(tzinfo=BEIJING_TZ)
-            else:
-                start = start.astimezone(BEIJING_TZ)
-            active_duration_map[row[0]] = round((now - start).total_seconds() / 3600, 1)
+            start_bj = to_beijing(start)  # 🚀 naive 按 UTC 转北京时间（修复多算8小时）
+            active_duration_map[row[0]] = working_duration_hours(start_bj, now, holidays)
 
     return [
         ProductResponse(