feat: add examples (01-08), fix index bars parsing, add ruff hook

- Add example scripts for all API categories (connection, market info,
  kline, minute, transaction, finance, block, fund flow)
- Fix GetIndexBarsCmd: index bar records have 4 extra bytes (advance/
  decline counts) that were not consumed, causing pos drift and
  corrupted dates/volumes for all records after the first
- Fix price_limits.py example (SecurityQuote has no name attr)
- Fix finance_info.py display (scientific notation -> formatted numbers)
- Add PostToolUse ruff hook (scripts/ruff_hook.py)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

examples/05_transaction/transaction_data.py

@@ -0,0 +1,15 @@
+"""演示：获取当日逐笔成交数据。"""
+
+import pandas as pd
+from xmtdx import TdxClient, Market
+
+with TdxClient.from_best_host() as c:
+    records = c.get_transaction_data(Market.SH, "600000", 0, 20)
+    df = pd.DataFrame([{
+        "时间": f"{r.hour:02d}:{r.minute:02d}",
+        "成交价": r.price,
+        "成交量": r.vol,
+        "方向": "买" if r.buyorsell == 0 else "卖",
+    } for r in records])
+    print(f"浦发银行最近 {len(df)} 笔成交:")
+    print(df.to_string(index=False))