业务日期端到端：状态库快照 + 下载写入 + 报告读库

- state_store: site_status 加 expected/actual/undelivered_business_date 列（建表+旧库迁移）；set_data_state 加可选 business_date（None 时保留，心跳不覆盖下载快照）
- runtime: dispatch_task 下载成功后快照业务日期（today−offset）；4 站 undelivered 一并补写 expected/actual/undelivered 三列（_site_undelivered_handler 内部连下绕过 dispatch，否则应到/实到业务日期丢失）
- expected_undelivered: 报告数据日期列改读状态库（_read_business_dates），退役 mtime 反推；KPI 卡 2-3-2-2 等宽对齐 + 柱状图图例 overlay 分行

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

runtime.py

@@ -16,7 +16,7 @@ import socket
 import subprocess
 import time
 import urllib.request
-from datetime import datetime
+from datetime import datetime, timedelta
 
 import yaml
 from playwright.sync_api import sync_playwright
@@ -490,6 +490,42 @@ TASK_HANDLERS = {
 }
 
 
+def _record_business_date(site, kind):
+    """下载成功后，把本次数据的业务日期快照写进状态库（供前端/报告显示「是哪天的数据」）。
+    业务日期 = 下载当天 − 该数据对应的日期偏移。__compare__ 无数据概念，跳过。
+
+    kind → 写入：
+      expected/actual：各写自己一列（偏移各取其列）。
+      undelivered：百世直供（恒 0）写 undelivered；4 站未到由 _site_undelivered_handler
+        内部连带下了 expected+actual（不经 dispatch，无业务日期写入），故此处一并补写
+        expected/actual/undelivered 三列——actual 用 actual 偏移、未到跟随 expected 偏移。
+    顺带置 ready=True，让前端不必等心跳即可反映下载成功；写入失败仅告警、不影响任务判定。"""
+    if site == "__compare__":
+        return
+    today = datetime.now().date()
+    now = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+
+    def _write(k, off):
+        biz = (today - timedelta(days=off)).strftime("%Y-%m-%d")
+        try:
+            state_store.set_data_state(
+                site, k, ready=True, generated_at=now, business_date=biz
+            )
+        except Exception as e:
+            print(f">> [状态] 写业务日期失败 {site}/{k}: {e}")
+
+    if kind == "expected":
+        _write("expected", state_store.get_offset(site, "expected"))
+    elif kind == "actual":
+        _write("actual", state_store.get_offset(site, "actual"))
+    elif site == "百世":
+        _write("undelivered", 0)
+    else:  # 4 站 undelivered：连带补写 expected/actual/undelivered 三列
+        _write("expected", state_store.get_offset(site, "expected"))
+        _write("actual", state_store.get_offset(site, "actual"))
+        _write("undelivered", state_store.get_offset(site, "expected"))
+
+
 def dispatch_task(ctx, task_spec):
     """执行一条任务。task_spec = {"site", "kind"}。返回 (status, error)。
 
@@ -513,6 +549,7 @@ def dispatch_task(ctx, task_spec):
         ret = handler(ctx)
         if ret is False:
             return (state_store.TASK_FAILED, "任务执行失败（重试耗尽）")
+        _record_business_date(site, kind)
         return (state_store.TASK_SUCCESS, None)
     except Exception as e:
         return (state_store.TASK_FAILED, str(e))