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/04_minute/minute_time_data.py

@@ -0,0 +1,14 @@
+"""演示：获取今日分时数据（240 条）。"""
+
+import pandas as pd
+from xmtdx import TdxClient, Market
+
+with TdxClient.from_best_host() as c:
+    bars = c.get_minute_time_data(Market.SH, "600000")
+    df = pd.DataFrame([{
+        "序号": i + 1,
+        "价格": bar.price,
+        "成交量": bar.vol,
+    } for i, bar in enumerate(bars)])
+    print(f"浦发银行今日分时，共 {len(df)} 条:")
+    print(df.to_string(index=False))