feat(backend): Phase 1 数据层 — Domain / Provider / Failover 审计 + 持久化 + 同步 CLI

- domain：市场数据实体（Stock / 交易日历 / 日线 / 复权 / 财务含 announce_date）+ Repository 与 MarketDataProvider Protocol
- 数据源：TushareProvider（归一化、重试、鉴权错误归类）、SinaProvider（备用，明确前复权口径与能力边界）、FailoverProvider + SyncLog 审计（禁止静默切换）
- 持久化：SQLAlchemy 2.x Models + Repository 实现（按业务键幂等 upsert、as_of_date 防未来函数过滤）+ Alembic 迁移
- CLI：uv run python -m app.cli.sync {basic|calendar|daily|financial|verify}，支持 --resume 断点续传
- 真实 Tushare 验证：stock 5556 / 交易日历 366 / daily+factor 242 / 财务 55；sync_log 审计完整
- 测试：38 passed（domain / provider / failover / repository / 未来函数 / 迁移），ruff clean

backend/tests/test_sina_provider.py

@@ -0,0 +1,77 @@
+"""新浪 Provider 测试：代码转换、JSONP 解析、能力边界（不触网）。"""
+
+from __future__ import annotations
+
+from datetime import date
+
+import pytest
+from app.infrastructure.data_sources.errors import (
+    DataSourceError,
+    DataSourceNotSupported,
+)
+from app.infrastructure.data_sources.sina import SinaProvider, _extract_jsonp, _to_sina_symbol
+
+_KLINE_OK = (
+    'var data=[{"day":"2024-08-30","open":"1700.0","high":"1720.0","low":"1690.0",'
+    '"close":"1710.0","volume":"20000"},{"day":"2024-08-31","open":"1710.0",'
+    '"high":"1725.0","low":"1705.0","close":"1720.0","volume":"18000"}]'
+)
+
+
+class _FakeResp:
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *exc):
+        return False
+
+    def read(self):
+        return _KLINE_OK.encode("utf-8")
+
+
+class _BoomResp(_FakeResp):
+    def read(self):
+        raise OSError("socket timeout")
+
+
+class TestSymbolMap:
+    def test_mapping(self) -> None:
+        assert _to_sina_symbol("600519.SH") == "sh600519"
+        assert _to_sina_symbol("000001.SZ") == "sz000001"
+        assert _to_sina_symbol("830001.BJ") == "bj830001"
+
+
+class TestJsonp:
+    def test_extract(self) -> None:
+        rows = _extract_jsonp(_KLINE_OK)
+        assert len(rows) == 2
+        assert rows[0]["close"] == "1710.0"
+
+    def test_bad_payload_raises(self) -> None:
+        with pytest.raises(DataSourceError, match="无法解析"):
+            _extract_jsonp("not jsonp")
+
+
+class TestGetDaily:
+    def test_ok_with_date_filter(self) -> None:
+        provider = SinaProvider(urlopen=lambda _url, **kw: _FakeResp())
+        bars = provider.get_daily("600519.SH", date(2024, 8, 30), date(2024, 8, 30))
+        assert len(bars) == 1
+        assert bars[0].close is not None
+        assert bars[0].symbol == "600519.SH"
+
+    def test_network_error_wrapped(self) -> None:
+        provider = SinaProvider(urlopen=lambda _url, **kw: _BoomResp())
+        with pytest.raises(DataSourceError, match="sina 请求失败"):
+            provider.get_daily("600519.SH", date(2024, 8, 1), date(2024, 8, 31))
+
+
+class TestCapabilities:
+    def test_not_supported(self) -> None:
+        provider = SinaProvider()
+        with pytest.raises(DataSourceNotSupported):
+            provider.get_stock_basic()
+        with pytest.raises(DataSourceNotSupported):
+            provider.get_adjust_factor("600519.SH", date(2024, 1, 1), date(2024, 1, 31))
+        with pytest.raises(DataSourceNotSupported):
+            provider.get_financial("600519.SH")