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/08_fund_flow/fund_flow.py

@@ -0,0 +1,19 @@
+"""演示：获取个股当日资金流向（基于 L1 逐笔数据统计）。
+
+资金分为四级: 超大(>100万)、大(20-100万)、中(4-20万)、小(<4万)。
+"""
+
+import pandas as pd
+from xmtdx import TdxClient, Market
+
+with TdxClient.from_best_host() as c:
+    flow = c.get_fund_flow(Market.SH, "600519")
+    df = pd.DataFrame([
+        {"级别": "超大单", "流入(亿)": flow.super_in / 1e8, "流出(亿)": flow.super_out / 1e8},
+        {"级别": "大单",   "流入(亿)": flow.large_in / 1e8, "流出(亿)": flow.large_out / 1e8},
+        {"级别": "中单",   "流入(亿)": flow.medium_in / 1e8, "流出(亿)": flow.medium_out / 1e8},
+        {"级别": "小单",   "流入(亿)": flow.small_in / 1e8, "流出(亿)": flow.small_out / 1e8},
+    ])
+    df["净流入(亿)"] = df["流入(亿)"] - df["流出(亿)"]
+    print("贵州茅台 当日资金流向:")
+    print(df.to_string(index=False))