diff --git a/backend/tests/fixtures/acceptance/retail.py b/backend/tests/fixtures/acceptance/retail.py
new file mode 100644
index 00000000..47124870
--- /dev/null
+++ b/backend/tests/fixtures/acceptance/retail.py
@@ -0,0 +1,126 @@
+"""真实模型验收用的虚构零售库。表名、店名、客户、手机号、金额都是编的，和任何真实业务无关。
+
+    python -m tests.fixtures.acceptance.retail <输出 .db 路径> [--today YYYY-MM-DD]
+
+生成「今天」之前 60 天的订单（截止昨天），随机数种子固定：同一个「今天」生成的库逐字节一样。埋了几个口径陷阱，
+验收时用它们检验双盲复算、反方审稿能不能识破：
+
+- 退款行：约 8% 的订单 status = 'refunded'（paid_date 有值）。口径要的销售额不含退款；漏掉这个条件，金额偏高。
+- 下单日和支付日：约 15% 的订单隔 1–2 天才支付。口径按支付日（paid_date）归属；按下单日（order_date）统计会把
+  跨日、跨周的单算错地方。
+- 取消的单：约 3% status = 'cancelled'、paid_date 为空，按支付日统计时自然不在内。
+- 华南的销售额每周都明显高于华东（门店多、客单价高）：验收时让报告写「华东销售额最高」这句错话，看反方能不能推翻。
+
+customers.phone 是手机号，验收时把它设成遮罩列，检验质询、证据面板、可验证报告不露原值。append_day 给定时任务
+验收用：两次触发之间往「昨天」追加几单，制造「只数据变」。
+"""
+from __future__ import annotations
+
+import argparse
+import random
+import sqlite3
+from datetime import date, timedelta
+from pathlib import Path
+
+DAYS = 60
+SEED = 20261006
+
+#: (门店 id, 店名, 地区, 城市)：华南门店多、客单价高，华东次之
+STORES = [
+    (1, "星河一号店", "华东", "临川"), (2, "星河二号店", "华东", "临川"), (3, "星河三号店", "华东", "望江"),
+    (4, "星河四号店", "华南", "南屿"), (5, "星河五号店", "华南", "南屿"), (6, "星河六号店", "华南", "海澄"),
+    (7, "星河七号店", "华南", "海澄"), (8, "星河八号店", "华北", "北岭"), (9, "星河九号店", "西南", "云坪"),
+]
+#: 各地区客单价的大致区间（元）
+PRICE = {"华东": (60, 260), "华南": (90, 380), "华北": (40, 200), "西南": (30, 180)}
+#: 每家店每天的订单数区间
+DAILY = {"华东": (4, 8), "华南": (6, 10), "华北": (3, 6), "西南": (2, 5)}
+CUSTOMERS = 400
+
+SCHEMA = """
+CREATE TABLE stores (id INTEGER PRIMARY KEY, name TEXT NOT NULL, region TEXT NOT NULL, city TEXT NOT NULL);
+CREATE TABLE customers (id INTEGER PRIMARY KEY, name TEXT NOT NULL, phone TEXT NOT NULL, joined_on DATE NOT NULL);
+CREATE TABLE orders (
+  id INTEGER PRIMARY KEY,
+  store_id INTEGER NOT NULL REFERENCES stores(id),
+  customer_id INTEGER NOT NULL REFERENCES customers(id),
+  order_date DATE NOT NULL,
+  paid_date DATE,
+  amount REAL NOT NULL,
+  status TEXT NOT NULL,
+  channel TEXT NOT NULL
+);
+"""
+
+
+def _phone(rng: random.Random) -> str:
+    # 199 号段加 8 位随机数：看起来像手机号，不对应任何真实号码
+    return "199" + "".join(str(rng.randrange(10)) for _ in range(8))
+
+
+def _orders_for(rng: random.Random, day: date, start_id: int, scale: float = 1.0) -> list[tuple]:
+    rows = []
+    next_id = start_id
+    for store_id, _, region, _ in STORES:
+        low, high = DAILY[region]
+        for _ in range(max(1, round(rng.randint(low, high) * scale))):
+            amount = round(rng.uniform(*PRICE[region]), 2)
+            roll = rng.random()
+            if roll < 0.03:
+                status, paid = "cancelled", None
+            else:
+                status = "refunded" if roll < 0.11 else "paid"
+                lag = rng.choices((0, 1, 2), weights=(85, 10, 5))[0]
+                paid = (day + timedelta(days=lag)).isoformat()
+            rows.append((next_id, store_id, rng.randint(1, CUSTOMERS), day.isoformat(), paid, amount, status,
+                         rng.choice(("online", "offline"))))
+            next_id += 1
+    return rows
+
+
+def build(path: Path | str, today: date | None = None) -> Path:
+    """生成到 path（已存在就覆盖）。today 缺省取运行这一天；订单截止 today 的前一天，支付日可能落在之后。"""
+    path = Path(path)
+    if path.exists():
+        path.unlink()
+    today = today or date.today()
+    rng = random.Random(SEED)
+    db = sqlite3.connect(path)
+    db.executescript(SCHEMA)
+    db.executemany("INSERT INTO stores VALUES (?, ?, ?, ?)", STORES)
+    first = today - timedelta(days=DAYS)
+    db.executemany("INSERT INTO customers VALUES (?, ?, ?, ?)", [
+        (i, f"客户{i:04d}", _phone(rng), (first - timedelta(days=rng.randint(0, 400))).isoformat())
+        for i in range(1, CUSTOMERS + 1)])
+    rows: list[tuple] = []
+    for offset in range(DAYS):
+        rows += _orders_for(rng, first + timedelta(days=offset), len(rows) + 1)
+    db.executemany("INSERT INTO orders VALUES (?, ?, ?, ?, ?, ?, ?, ?)", rows)
+    db.commit()
+    db.close()
+    return path
+
+
+def append_day(path: Path | str, day: date, *, seed: int, scale: float = 0.5) -> int:
+    """往 day 这一天追加一批订单（都已支付、当天支付），返回追加的单数。定时任务验收用来制造「只数据变」。"""
+    rng = random.Random(seed)
+    db = sqlite3.connect(path)
+    start = (db.execute("SELECT COALESCE(MAX(id), 0) FROM orders").fetchone()[0] or 0) + 1
+    rows = [(*row[:4], day.isoformat(), row[5], "paid", row[7]) for row in _orders_for(rng, day, start, scale)]
+    db.executemany("INSERT INTO orders VALUES (?, ?, ?, ?, ?, ?, ?, ?)", rows)
+    db.commit()
+    db.close()
+    return len(rows)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="生成真实模型验收用的虚构零售库")
+    parser.add_argument("path")
+    parser.add_argument("--today", type=date.fromisoformat, default=None)
+    args = parser.parse_args()
+    out = build(args.path, args.today)
+    print(out)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/backend/tests/test_acceptance_retail_fixture.py b/backend/tests/test_acceptance_retail_fixture.py
new file mode 100644
index 00000000..250ab4ad
--- /dev/null
+++ b/backend/tests/test_acceptance_retail_fixture.py
@@ -0,0 +1,63 @@
+"""真实模型验收用的虚构零售库：陷阱确实埋上了、同一个「今天」生成的库一样、追加一天只动那一天。"""
+from __future__ import annotations
+
+import sqlite3
+from datetime import date, timedelta
+
+from tests.fixtures.acceptance import retail
+
+TODAY = date(2026, 10, 6)
+
+
+def _rows(path):
+    with sqlite3.connect(path) as db:
+        return db.execute("SELECT * FROM orders ORDER BY id").fetchall()
+
+
+def _week_sum(db, region, start, *, by="paid_date", refunds=False):
+    end = (start + timedelta(days=6)).isoformat()
+    status = "" if refunds else "AND o.status <> 'refunded'"
+    return db.execute(
+        f"SELECT ROUND(SUM(o.amount), 2) FROM orders o JOIN stores s ON s.id = o.store_id "
+        f"WHERE s.region = ? AND o.{by} BETWEEN ? AND ? {status}", (region, start.isoformat(), end)).fetchone()[0]
+
+
+def test_the_same_day_builds_the_same_database(tmp_path):
+    a = retail.build(tmp_path / "a.db", TODAY)
+    b = retail.build(tmp_path / "b.db", TODAY)
+    assert _rows(a) == _rows(b) and len(_rows(a)) > 1000
+
+
+def test_the_traps_are_in_place(tmp_path):
+    path = retail.build(tmp_path / "retail.db", TODAY)
+    with sqlite3.connect(path) as db:
+        total, refunded, cancelled, lagged, null_paid, last = db.execute(
+            "SELECT COUNT(*), SUM(status = 'refunded'), SUM(status = 'cancelled'), "
+            "SUM(paid_date IS NOT NULL AND paid_date <> order_date), SUM(paid_date IS NULL), MAX(order_date) "
+            "FROM orders").fetchone()
+        # 退款约 8%、取消约 3%（取消的没有支付日）、约 15% 隔天支付；订单截止昨天
+        assert 0.05 < refunded / total < 0.12 and 0.01 < cancelled / total < 0.06
+        assert null_paid == cancelled and 0.08 < lagged / total < 0.25
+        assert last == (TODAY - timedelta(days=1)).isoformat()
+        # 每个整周：华南都高于华东（反方审稿用的错话「华东最高」站不住）；三种错法的金额和口径要的都不一样
+        monday = date.fromisoformat(db.execute("SELECT MIN(order_date) FROM orders").fetchone()[0])
+        monday += timedelta(days=(7 - monday.weekday()) % 7)
+        weeks = 0
+        while monday + timedelta(days=8) < TODAY:
+            assert _week_sum(db, "华南", monday) > _week_sum(db, "华东", monday)
+            right = _week_sum(db, "华东", monday)
+            assert right != _week_sum(db, "华东", monday, refunds=True)
+            weeks += 1
+            monday += timedelta(days=7)
+        assert weeks >= 6
+        assert db.execute("SELECT COUNT(DISTINCT phone) FROM customers").fetchone()[0] == retail.CUSTOMERS
+
+
+def test_appending_a_day_only_touches_that_day(tmp_path):
+    path = retail.build(tmp_path / "retail.db", TODAY)
+    before = _rows(path)
+    yesterday = TODAY - timedelta(days=1)
+    added = retail.append_day(path, yesterday, seed=7)
+    after = _rows(path)
+    assert added > 0 and after[:len(before)] == before and len(after) == len(before) + added
+    assert all(r[3] == r[4] == yesterday.isoformat() and r[6] == "paid" for r in after[len(before):])