feat: 仪表盘+催办在休息日跳过填报检查

- 新增 is_working_day() 工具函数，自动跳过周末 + 可配置法定假日
- 仪表盘填报进度新增 is_rest_day 字段，休息日显示灰「休」印章
- 催办调度改用 is_working_day() 替代原始 weekday 检查
- 系统设置新增「法定节假日」配置卡片，支局长可管理假日日期

Co-Authored-By: Claude <noreply@anthropic.com>

backend/app/services/dashboard.py

@@ -11,7 +11,8 @@ from app.models.mini_business import MiniBusiness
 from app.models.key_visit import KeyVisit
 from app.models.daily_note import DailyNote
 from app.models.leave import Leave
-from app.utils.timezone import today_cst
+from app.models.system_config import SystemConfig
+from app.utils.timezone import today_cst, is_working_day
 
 
 def get_week_range(reference_date: date | None = None):
@@ -78,8 +79,22 @@ async def get_reporting_progress(db: AsyncSession, reference_date: date | None =
     )
     visit_map = {str(uid): cnt for uid, cnt in visits_result.all()}
 
+    # Load holiday config
+    holiday_row = await db.get(SystemConfig, "holidays")
+    holidays: set[date] = set()
+    if holiday_row and holiday_row.value:
+        for s in holiday_row.value.split(","):
+            s = s.strip()
+            if s:
+                try:
+                    holidays.add(date.fromisoformat(s))
+                except ValueError:
+                    pass
+
     # Query leave records for today — build a set of managers on leave
     today = today_cst()
+    is_rest = not is_working_day(today, holidays)
+
     leaves_result = await db.execute(
         select(Leave).where(and_(
             Leave.start_date <= today,
@@ -107,6 +122,7 @@ async def get_reporting_progress(db: AsyncSession, reference_date: date | None =
             "completed": count >= expected,
             "has_reported_today": False,  # Will be set below
             "on_leave": leave is not None,
+            "is_rest_day": is_rest,
             "leave_info": {
                 "leave_type": leave.leave_type,
                 "start_date": str(leave.start_date),