feat: add offline data write-back and sync commands, bump to v1.6.0

- Add write_daily.py: encode/append daily bars to .day files
- Add write_ex_daily.py: encode/append extended market daily bars
- Add write_min_bar.py: encode/append minute bars (.5/.lc1/.lc5)
- Add sync-daily CLI: sync single stock with pagination support
- Add sync-all CLI: one-command sync for all SH/SZ .day files
- Update README with sync commands and Python write API docs
- 50 new unit tests covering encode round-trip, append dedup, edge cases
- Bump version 1.5.0 -> 1.6.0

tests/unit/test_write_min_bar.py

@@ -0,0 +1,276 @@
+"""离线分钟线写入测试（纯离线，无网络）。"""
+
+from __future__ import annotations
+
+import struct
+from pathlib import Path
+
+from easy_tdx.models.bar import SecurityBar
+from easy_tdx.offline.min_bar import (
+    _LC_MIN_FMT,
+    _MIN_FMT,
+    _decode_tdx_date,
+    _decode_tdx_time,
+    read_5min_bars,
+    read_lc_min_bars,
+)
+from easy_tdx.offline.write_min_bar import (
+    append_5min_bars,
+    append_lc_min_bars,
+    encode_5min_bar,
+    encode_lc_min_bar,
+    get_last_5min_bar_datetime,
+    get_last_lc_min_bar_datetime,
+)
+
+# ---------------------------------------------------------------------------
+# helpers
+# ---------------------------------------------------------------------------
+
+
+def _make_min_bar(
+    year: int = 2026,
+    month: int = 6,
+    day: int = 6,
+    hour: int = 9,
+    minute: int = 30,
+    open_: float = 10.25,
+    high: float = 10.50,
+    low: float = 10.10,
+    close: float = 10.30,
+    vol: float = 5000.0,
+    amount: float = 51250.0,
+) -> SecurityBar:
+    return SecurityBar(
+        open=open_,
+        close=close,
+        high=high,
+        low=low,
+        vol=vol,
+        amount=amount,
+        year=year,
+        month=month,
+        day=day,
+        hour=hour,
+        minute=minute,
+    )
+
+
+def _encode_tdx_date(year: int, month: int, day: int) -> int:
+    return (year - 2004) * 2048 + month * 100 + day
+
+
+def _encode_tdx_time(hour: int, minute: int) -> int:
+    return hour * 60 + minute
+
+
+def _make_raw_5min_bar(
+    year: int = 2026,
+    month: int = 6,
+    day: int = 6,
+    hour: int = 9,
+    minute: int = 30,
+    open_int: int = 1025,
+    high_int: int = 1050,
+    low_int: int = 1010,
+    close_int: int = 1030,
+    amount: float = 51250.0,
+    vol_int: int = 5000,
+) -> bytes:
+    return _MIN_FMT.pack(
+        _encode_tdx_date(year, month, day),
+        _encode_tdx_time(hour, minute),
+        open_int,
+        high_int,
+        low_int,
+        close_int,
+        amount,
+        vol_int,
+        0,
+    )
+
+
+def _make_raw_lc_min_bar(
+    year: int = 2026,
+    month: int = 6,
+    day: int = 6,
+    hour: int = 9,
+    minute: int = 30,
+    open_: float = 10.25,
+    high: float = 10.50,
+    low: float = 10.10,
+    close: float = 10.30,
+    amount: float = 51250.0,
+    vol: int = 5000,
+) -> bytes:
+    return _LC_MIN_FMT.pack(
+        _encode_tdx_date(year, month, day),
+        _encode_tdx_time(hour, minute),
+        open_,
+        high,
+        low,
+        close,
+        amount,
+        vol,
+        0,
+    )
+
+
+# ===========================================================================
+# .5 文件 (5 分钟线)
+# ===========================================================================
+
+
+class TestEncode5minBar:
+    def test_output_length(self) -> None:
+        bar = _make_min_bar()
+        result = encode_5min_bar(bar)
+        assert len(result) == 32
+
+    def test_date_encoding(self) -> None:
+        bar = _make_min_bar(year=2026, month=6, day=5)
+        result = encode_5min_bar(bar)
+        date_num = struct.unpack_from("<H", result, 0)[0]
+        yr, mo, dy = _decode_tdx_date(date_num)
+        assert (yr, mo, dy) == (2026, 6, 5)
+
+    def test_time_encoding(self) -> None:
+        bar = _make_min_bar(hour=14, minute=30)
+        result = encode_5min_bar(bar)
+        time_num = struct.unpack_from("<H", result, 2)[0]
+        h, m = _decode_tdx_time(time_num)
+        assert (h, m) == (14, 30)
+
+    def test_price_encoding(self) -> None:
+        """5 分钟线 OHLC 整数 × 100。"""
+        bar = _make_min_bar(open_=10.25)
+        result = encode_5min_bar(bar)
+        open_int = struct.unpack_from("<I", result, 4)[0]
+        assert open_int == 1025
+
+
+class Test5minRoundTrip:
+    def test_single_bar_round_trip(self, tmp_path: Path) -> None:
+        bar = _make_min_bar(open_=10.25, close=10.30, vol=5000.0, amount=51250.0)
+        encoded = encode_5min_bar(bar)
+
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(encoded)
+
+        bars = read_5min_bars(filepath)
+        assert len(bars) == 1
+        b = bars[0]
+        assert abs(b.open - 10.25) < 0.01
+        assert abs(b.close - 10.30) < 0.01
+        assert abs(b.vol - 5000.0) < 1.0
+        assert b.hour == 9 and b.minute == 30
+
+    def test_multiple_bars(self, tmp_path: Path) -> None:
+        bars_in = [
+            _make_min_bar(hour=9, minute=30),
+            _make_min_bar(hour=9, minute=35),
+            _make_min_bar(hour=9, minute=40),
+        ]
+        encoded = b"".join(encode_5min_bar(b) for b in bars_in)
+
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(encoded)
+
+        bars_out = read_5min_bars(filepath)
+        assert len(bars_out) == 3
+        assert bars_out[0].minute == 30
+        assert bars_out[2].minute == 40
+
+
+class TestGetLast5minBarDatetime:
+    def test_returns_last_datetime(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(_make_raw_5min_bar(year=2026, month=6, day=5, hour=15, minute=0))
+        result = get_last_5min_bar_datetime(filepath)
+        assert result == (2026, 6, 5, 15, 0)
+
+    def test_returns_none_for_empty(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(b"")
+        assert get_last_5min_bar_datetime(filepath) is None
+
+
+class TestAppend5minBars:
+    def test_append_to_existing(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(_make_raw_5min_bar(hour=9, minute=30))
+
+        new_bar = _make_min_bar(hour=9, minute=35)
+        written = append_5min_bars(filepath, [new_bar])
+        assert written == 1
+
+        bars = read_5min_bars(filepath)
+        assert len(bars) == 2
+
+    def test_skips_duplicate(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.5"
+        filepath.write_bytes(_make_raw_5min_bar(hour=9, minute=30))
+
+        new_bar = _make_min_bar(hour=9, minute=30)  # same datetime
+        written = append_5min_bars(filepath, [new_bar])
+        assert written == 0
+
+
+# ===========================================================================
+# .lc1 / .lc5 文件
+# ===========================================================================
+
+
+class TestEncodeLcMinBar:
+    def test_output_length(self) -> None:
+        bar = _make_min_bar()
+        result = encode_lc_min_bar(bar)
+        assert len(result) == 32
+
+    def test_float_prices_preserved(self) -> None:
+        bar = _make_min_bar(open_=10.255)
+        result = encode_lc_min_bar(bar)
+        (op,) = struct.unpack_from("<f", result, 4)
+        assert abs(op - 10.255) < 0.001
+
+
+class TestLcMinRoundTrip:
+    def test_single_bar_round_trip(self, tmp_path: Path) -> None:
+        bar = _make_min_bar(open_=10.255, close=10.31, vol=5000.0, amount=51250.0)
+        encoded = encode_lc_min_bar(bar)
+
+        filepath = tmp_path / "sh600000.lc1"
+        filepath.write_bytes(encoded)
+
+        bars = read_lc_min_bars(filepath)
+        assert len(bars) == 1
+        b = bars[0]
+        assert abs(b.open - 10.255) < 0.001
+        assert abs(b.close - 10.31) < 0.001
+        assert b.hour == 9 and b.minute == 30
+
+
+class TestGetLastLcMinBarDatetime:
+    def test_returns_last_datetime(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.lc1"
+        filepath.write_bytes(_make_raw_lc_min_bar(year=2026, month=6, day=5, hour=14, minute=55))
+        result = get_last_lc_min_bar_datetime(filepath)
+        assert result == (2026, 6, 5, 14, 55)
+
+    def test_returns_none_for_empty(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.lc1"
+        filepath.write_bytes(b"")
+        assert get_last_lc_min_bar_datetime(filepath) is None
+
+
+class TestAppendLcMinBars:
+    def test_append_to_existing(self, tmp_path: Path) -> None:
+        filepath = tmp_path / "sh600000.lc1"
+        filepath.write_bytes(_make_raw_lc_min_bar(hour=9, minute=30))
+
+        new_bar = _make_min_bar(hour=9, minute=31)
+        written = append_lc_min_bars(filepath, [new_bar])
+        assert written == 1
+
+        bars = read_lc_min_bars(filepath)
+        assert len(bars) == 2