release: v1.16.2 — 三轮审计质量加固（B6.9→A7.9）

经三轮代码审计后的综合质量加固版本，覆盖协议核心层、数据正确性、
错误处理、测试真实度与可维护性。761 单测全绿（+58），ruff/mypy 全过。

主要修复：
- 离线 .day 写入原子化（fsync + _repair_tail + 读取校验，CQS 守住）
- 回测止损前视偏差（延迟下一根开盘 + 跳空保护）
- VWAP 权重索引 / bar_time fail-fast / 绩效除零保护
- 闭包绑定 / 路径穿越 / naive datetime 跨时区 / ruff UP038

重构：
- 抽 AsyncHeartbeatMixin 收敛 4 处心跳副本（12→1）
- 统一 _RETRY_DELAYS 退避序列 / scanner 失败可观测性

新增 5 个测试文件 + 公共 API 类型契约，CI 加 Windows 矩阵 +
trusted publishing 签名 + 锁文件。

详见 CHANGELOG.md

tests/unit/test_codec_bitmap.py

@@ -0,0 +1,126 @@
+"""codec/bitmap.py 单元测试 —— MAC 协议字段位图编解码。
+
+之前 bitmap.py（~490 行）零测试（审计报告 #9）。本文件覆盖：
+FieldBit 字段属性、PresetField 组合、FieldSelection 去重、
+build_bitmap 20 字节输出、get_active_fields 往返解析。
+
+风格参照 test_codec_frame.py：纯函数式、无 mock、struct 构造输入。
+"""
+
+from __future__ import annotations
+
+from easy_tdx.codec.bitmap import (
+    FieldBit,
+    FieldSelection,
+    PresetField,
+    build_bitmap,
+    build_exclude_flags,
+    get_active_fields,
+    normalize_fields,
+)
+
+
+class TestFieldBit:
+    def test_field_name_is_lower(self) -> None:
+        assert FieldBit.PRE_CLOSE.field_name == "pre_close"
+        assert FieldBit.OPEN.field_name == "open"
+
+    def test_fmt_and_desc_attached(self) -> None:
+        assert FieldBit.OPEN.fmt == "<f"
+        assert FieldBit.OPEN.desc == "开盘价"
+        assert FieldBit.VOL.fmt == "<I"
+
+    def test_value_is_bit_position(self) -> None:
+        assert FieldBit.PRE_CLOSE == 0x00
+        assert FieldBit.OPEN == 0x01
+
+
+class TestPresetField:
+    def test_ohlc_contains_four_fields(self) -> None:
+        names = {f.name for f in PresetField.OHLC.value}
+        assert names == {"OPEN", "HIGH", "LOW", "CLOSE"}
+
+    def test_chain_plus_combines(self) -> None:
+        combined = PresetField.OHLC + FieldBit.VOL
+        sel = normalize_fields(combined)
+        bits = {b for b in sel}
+        assert FieldBit.VOL in bits
+        assert FieldBit.OPEN in bits
+
+    def test_chain_or_combines(self) -> None:
+        combined = PresetField.OHLC | PresetField.VOLUME
+        sel = normalize_fields(combined)
+        bits = {b for b in sel}
+        assert FieldBit.VOL in bits
+        assert FieldBit.AMOUNT in bits
+
+
+class TestFieldSelection:
+    def test_dedup_preserves_order(self) -> None:
+        sel = FieldSelection(FieldBit.OPEN, FieldBit.OPEN, FieldBit.HIGH)
+        bits = list(sel)
+        assert bits == [FieldBit.OPEN, FieldBit.HIGH]
+
+    def test_empty_selection(self) -> None:
+        assert list(FieldSelection()) == []
+
+
+class TestBuildBitmap:
+    def test_single_field_sets_correct_bit(self) -> None:
+        # FieldBit.OPEN == 0x01，bit 1 应被置位
+        ba = build_bitmap(FieldBit.OPEN)
+        assert len(ba) == 20
+        assert ba[0] == 0b0000_0010  # bit 1
+        # 控制区 4 字节默认 0
+        assert bytes(ba[16:20]) == b"\x00\x00\x00\x00"
+
+    def test_multiple_fields_or(self) -> None:
+        ba = build_bitmap(PresetField.OHLC)
+        assert len(ba) == 20
+        # OPEN(1)+HIGH(2)+LOW(3)+CLOSE(4) → bit 1,2,3,4 → 0b11110 = 30
+        assert ba[0] == 0b0001_1110
+
+    def test_exclude_flags_appended(self) -> None:
+        ba = build_bitmap(FieldBit.OPEN, exclude_flags=0x1234)
+        assert len(ba) == 20
+        assert bytes(ba[16:20]) == b"\x34\x12\x00\x00"
+
+    def test_debug_preset_all_ff(self) -> None:
+        ba = build_bitmap(PresetField.DEBUG)
+        assert ba == bytearray(b"\xff" * 20)
+
+
+class TestGetActiveFields:
+    def test_roundtrip(self) -> None:
+        original = PresetField.OHLC
+        ba = build_bitmap(original)
+        active = get_active_fields(bytes(ba[:16]))
+        active_names = {f.name for f, _ in active}
+        assert active_names == {"OPEN", "HIGH", "LOW", "CLOSE"}
+
+    def test_empty_bitmap(self) -> None:
+        active = get_active_fields(b"\x00" * 16)
+        assert active == []
+
+    def test_fmt_returned(self) -> None:
+        ba = build_bitmap(FieldBit.VOL)
+        active = get_active_fields(bytes(ba[:16]))
+        assert len(active) == 1
+        field, fmt = active[0]
+        assert field == FieldBit.VOL
+        assert fmt == "<I"
+
+    def test_sorted_by_bit_position(self) -> None:
+        # 故意逆序传入
+        ba = build_bitmap([FieldBit.CLOSE, FieldBit.OPEN, FieldBit.HIGH])
+        active = get_active_fields(bytes(ba[:16]))
+        positions = [f.value for f, _ in active]
+        assert positions == sorted(positions)
+
+
+class TestBuildExcludeFlags:
+    def test_zero(self) -> None:
+        assert build_exclude_flags(0) == b"\x00\x00\x00\x00"
+
+    def test_value(self) -> None:
+        assert build_exclude_flags(0xFF) == b"\xff\x00\x00\x00"