fix: resolve all CI mypy (265→0) and ruff (26→0) errors

- pyproject.toml: add mypy overrides for pandas/tabulate/matplotlib stubs,
  disable strict checking for vendored MyTT library
- config.py: use cast() for dict[str, Any] .get() returns
- beichi.py: widen _calc_bi_force param to BI | XD, import XD
- backtest/cli.py: split combo/single strategy into separate typed variables
- backtest/combo.py: add bool_array() helper for numpy return types
- chanlun/analyser.py: type ignore for pandas row access, fix dict type arg
- unified.py: change fields param from object to Any
- ex/mac_client.py: add type args to list literals
- cli/cmd_offline.py: wrap int market as Market enum before API call
- cli/cmd_chanlun.py: fix dict type arg
- offline/write_*.py: explicit int() cast for struct.unpack returns
- MyTT.py: fix line-too-long comments, UP038 isinstance syntax
- tests: fix E712 (==False → ~mask), E741 (noqa), F841, import sorting
- ruff format applied across codebase

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/easy_tdx/cli/cmd_offline.py

@@ -493,8 +493,9 @@ def _fetch_all_daily_bars(
     Returns:
         SecurityBar 列表（按日期升序）。
     """
-    from ..models.enums import KlineCategory
+    from ..models.enums import KlineCategory, Market
 
+    mkt = Market(market)
     fetch_fn = client.get_index_bars if is_index else client.get_security_bars
 
     all_bars: list[SecurityBar] = []
@@ -503,7 +504,7 @@ def _fetch_all_daily_bars(
     max_pages = 50 if need_full else 1  # 50 页 = 40000 条，足够覆盖 A 股全部历史
 
     for _ in range(max_pages):
-        df = fetch_fn(market, code, KlineCategory.DAY, start, page_size)
+        df = fetch_fn(mkt, code, KlineCategory.DAY, start, page_size)
         if df.empty:
             break
         all_bars.extend(_df_to_bars(df))