feat: 修复daily历史覆盖度缺口+增加覆盖度校验

- 新增 repair_daily_backfill.py：按daily_basic基准检测并补拉覆盖不足交易日
  （解决2012-2013沪市+创业板整年缺失问题，断点续传日期级检测无法发现）
- importer.py: 新增 check_daily_coverage() 覆盖度审计函数
- incremental_import.py: 增量导入后自动跑覆盖度校验并告警
- 数据批量导入.ipynb: 增加数据完整性检验单元格

quantitative_data/importer.py

@@ -1566,6 +1566,70 @@ def get_missing_daily_dates(
             conn.close()
 
 
+def check_daily_coverage(
+    start_date: Optional[str] = None,
+    end_date: Optional[str] = None,
+    conn=None,
+    tolerance: float = 0.05,
+) -> List[Dict]:
+    """
+    检查 daily 表每日覆盖度（以 daily_basic 为基准，单条 SQL 聚合）。
+
+    背景：resume_daily_by_date 只做「日期级」缺失检测（NOT EXISTS trade_date），
+    若某交易日只有部分股票入库（如 2012-2013 沪市+创业板缺失），会误判为"已完整"，
+    导致覆盖度缺口永不补拉。本函数做「覆盖度级」校验：
+
+        daily 当日股票数 < daily_basic 当日股票数 × (1 - tolerance) → 判定覆盖不足
+
+    返回: [{"trade_date", "daily_cnt", "daily_basic_cnt", "coverage_pct"}, ...]
+    """
+    if start_date is None:
+        start_date = START_DATE
+    if end_date is None:
+        end_date = END_DATE
+
+    own_conn = conn is None
+    if own_conn:
+        conn = get_pg_connection()
+
+    try:
+        cursor = conn.cursor()
+        cursor.execute(
+            """
+            SELECT db.trade_date,
+                   COALESCE(d.cnt, 0) AS daily_cnt,
+                   db.cnt AS db_cnt,
+                   ROUND(COALESCE(d.cnt, 0)::numeric / db.cnt * 100, 1) AS coverage_pct
+            FROM (SELECT trade_date, COUNT(DISTINCT ts_code) AS cnt
+                  FROM daily_basic
+                  WHERE trade_date BETWEEN %s AND %s
+                  GROUP BY trade_date) db
+            LEFT JOIN (SELECT trade_date, COUNT(DISTINCT ts_code) AS cnt
+                       FROM daily
+                       WHERE trade_date BETWEEN %s AND %s
+                       GROUP BY trade_date) d
+              ON d.trade_date = db.trade_date
+            WHERE COALESCE(d.cnt, 0) < db.cnt * (1 - %s)
+            ORDER BY db.trade_date
+            """,
+            (start_date, end_date, start_date, end_date, tolerance),
+        )
+        rows = [
+            {
+                "trade_date": r[0].strftime("%Y-%m-%d") if hasattr(r[0], "strftime") else str(r[0])[:10],
+                "daily_cnt": r[1],
+                "daily_basic_cnt": r[2],
+                "coverage_pct": float(r[3]),
+            }
+            for r in cursor.fetchall()
+        ]
+        cursor.close()
+        return rows
+    finally:
+        if own_conn:
+            conn.close()
+
+
 def resume_daily_by_date(
     start_date: Optional[str] = None,
     end_date: Optional[str] = None,