✨ feat(tsl-api-reference): expand and reorganize api catalog

Flatten builtin pages, add third-party and platform scopes, and import financial and data warehouse references.

Keep the existing generated index without rebuilding after signature normalization.

skills/tsl-api-reference/references/codegen/dotnet/financial/financial_engineering-arbitrage.md

@@ -0,0 +1,17 @@
+# 金融 / 金融工程 / 套利
+
+## `etf50SampleData()`
+
+声明：function
+
+50ETF样本的实时买1量和卖1量
+
+返回：table_array
+
+### 示例
+
+范例01：调用 ETF50SampleData
+
+```tsl
+Return ETF50SampleData();
+```