feat(backend): 生产总天数返回自然天+工作日两个口径

- ProductResponse 加 production_days(自然天)/production_days_workdays(工作日)
- get_all_products 计算：自然天自创建至今，工作日用 working_duration_hours 排除周末/节假日
- FlowDevice 加 total_days/total_workdays(设备生产总天数，自最早介入至今)

backend/app/services/analytics_service.py

@@ -54,6 +54,8 @@ class FlowDevice(BaseModel):
     spec_model: str
     lead_time: float   # 设备生命周期总时长（小时）= max_end - min_start
     started_at: str    # 设备最早介入时间（T0），格式 MM-DD HH:mm
+    total_days: int = 0       # 设备生产总天数（自然天，自最早介入至今）
+    total_workdays: int = 0   # 设备生产总天数（工作日，排除周末/节假日）
 
 
 class FlowSeries(BaseModel):
@@ -394,12 +396,30 @@ async def get_flow_compare(
         idx: round((max_end_by_device[idx] - t0_by_device[idx]).total_seconds() / 3600, 1)
         for idx in t0_by_device
     }
+    # 🔧 设备生产总天数（自然天 + 工作日，自最早介入至今）
+    import math
+    from app.core.time_utils import to_beijing as _tb, working_duration_hours as _wdh
+    from app.models.holiday import Holiday as _Holiday
+    hres = await db.execute(select(_Holiday.day))
+    _holidays = {r[0] for r in hres}
+
+    def _total_days(t0):
+        t0_bj = _tb(t0)
+        if not t0_bj:
+            return 1, 1
+        natural = max(1, math.ceil((now - t0_bj).total_seconds() / 86400))
+        workdays = max(1, math.ceil(_wdh(t0_bj, now, _holidays) / 24))
+        return natural, workdays
+
+    days_map = {i: _total_days(t0_by_device[i]) for i in t0_by_device}
     devices = [
         FlowDevice(
             product_sn=d.product_sn, external_serial=d.external_serial,
             material_name=d.material_name, spec_model=d.spec_model,
             lead_time=lead_time_by_index.get(i, 0.0),
             started_at=t0_by_device[i].strftime("%m-%d %H:%M") if i in t0_by_device else "",
+            total_days=days_map.get(i, (1, 1))[0],
+            total_workdays=days_map.get(i, (1, 1))[1],
         )
         for i, d in enumerate(devices)
     ]