feat: integrate quantitative, calendar, market data endpoints

Add 3 new service layers and route modules:
- quantitative_service: Sharpe ratio, CAPM, normality tests, unit root tests
- calendar_service: earnings/dividends/IPO/splits calendars, estimates, SEC ownership
- market_service: ETF, index, crypto, forex, options, futures data

Total endpoints: 50. All use free providers (yfinance, SEC).
Update README with comprehensive endpoint documentation.

calendar_service.py

@@ -0,0 +1,159 @@
+"""Calendar events (earnings, dividends, IPOs, splits), screening, and ownership."""
+
+import asyncio
+import logging
+from typing import Any
+
+from openbb import obb
+
+logger = logging.getLogger(__name__)
+
+
+async def get_earnings_calendar(
+    start_date: str | None = None, end_date: str | None = None
+) -> list[dict[str, Any]]:
+    """Get upcoming earnings announcements."""
+    try:
+        kwargs: dict[str, Any] = {}
+        if start_date:
+            kwargs["start_date"] = start_date
+        if end_date:
+            kwargs["end_date"] = end_date
+        result = await asyncio.to_thread(obb.equity.calendar.earnings, **kwargs)
+        return _to_list(result)
+    except Exception:
+        logger.warning("Earnings calendar failed", exc_info=True)
+        return []
+
+
+async def get_dividend_calendar(
+    start_date: str | None = None, end_date: str | None = None
+) -> list[dict[str, Any]]:
+    """Get upcoming dividend dates."""
+    try:
+        kwargs: dict[str, Any] = {}
+        if start_date:
+            kwargs["start_date"] = start_date
+        if end_date:
+            kwargs["end_date"] = end_date
+        result = await asyncio.to_thread(obb.equity.calendar.dividend, **kwargs)
+        return _to_list(result)
+    except Exception:
+        logger.warning("Dividend calendar failed", exc_info=True)
+        return []
+
+
+async def get_ipo_calendar(
+    start_date: str | None = None, end_date: str | None = None
+) -> list[dict[str, Any]]:
+    """Get upcoming IPO dates."""
+    try:
+        kwargs: dict[str, Any] = {}
+        if start_date:
+            kwargs["start_date"] = start_date
+        if end_date:
+            kwargs["end_date"] = end_date
+        result = await asyncio.to_thread(obb.equity.calendar.ipo, **kwargs)
+        return _to_list(result)
+    except Exception:
+        logger.warning("IPO calendar failed", exc_info=True)
+        return []
+
+
+async def get_splits_calendar(
+    start_date: str | None = None, end_date: str | None = None
+) -> list[dict[str, Any]]:
+    """Get upcoming stock split dates."""
+    try:
+        kwargs: dict[str, Any] = {}
+        if start_date:
+            kwargs["start_date"] = start_date
+        if end_date:
+            kwargs["end_date"] = end_date
+        result = await asyncio.to_thread(obb.equity.calendar.splits, **kwargs)
+        return _to_list(result)
+    except Exception:
+        logger.warning("Splits calendar failed", exc_info=True)
+        return []
+
+
+async def get_analyst_estimates(symbol: str) -> dict[str, Any]:
+    """Get analyst consensus estimates for a symbol."""
+    try:
+        result = await asyncio.to_thread(
+            obb.equity.estimates.consensus, symbol, provider="yfinance"
+        )
+        items = _to_list(result)
+        return {"symbol": symbol, "estimates": items}
+    except Exception:
+        logger.warning("Analyst estimates failed for %s", symbol, exc_info=True)
+        return {"symbol": symbol, "estimates": []}
+
+
+async def get_share_statistics(symbol: str) -> dict[str, Any]:
+    """Get share statistics (float, shares outstanding, etc.)."""
+    try:
+        result = await asyncio.to_thread(
+            obb.equity.ownership.share_statistics, symbol, provider="yfinance"
+        )
+        items = _to_list(result)
+        return items[0] if items else {}
+    except Exception:
+        logger.warning("Share statistics failed for %s", symbol, exc_info=True)
+        return {}
+
+
+async def get_insider_trading(symbol: str) -> list[dict[str, Any]]:
+    """Get insider trading data from SEC (free)."""
+    try:
+        result = await asyncio.to_thread(
+            obb.equity.ownership.insider_trading, symbol, provider="sec"
+        )
+        return _to_list(result)
+    except Exception:
+        logger.warning("SEC insider trading failed for %s", symbol, exc_info=True)
+        return []
+
+
+async def get_institutional_holders(symbol: str) -> list[dict[str, Any]]:
+    """Get institutional holders from SEC 13F filings."""
+    try:
+        result = await asyncio.to_thread(
+            obb.equity.ownership.form_13f, symbol, provider="sec"
+        )
+        return _to_list(result)
+    except Exception:
+        logger.warning("13F data failed for %s", symbol, exc_info=True)
+        return []
+
+
+async def screen_stocks() -> list[dict[str, Any]]:
+    """Screen stocks using available screener."""
+    try:
+        result = await asyncio.to_thread(
+            obb.equity.screener, provider="yfinance"
+        )
+        return _to_list(result)
+    except Exception:
+        logger.warning("Stock screener failed", exc_info=True)
+        return []
+
+
+def _to_list(result: Any) -> list[dict[str, Any]]:
+    """Convert OBBject result to list of dicts."""
+    if result is None or result.results is None:
+        return []
+    items = result.results
+    if not isinstance(items, list):
+        items = [items]
+    out = []
+    for item in items:
+        if hasattr(item, "model_dump"):
+            d = item.model_dump()
+        else:
+            d = vars(item) if vars(item) else {}
+        for k, v in d.items():
+            if hasattr(v, "isoformat"):
+                d[k] = v.isoformat()
+        out.append(d)
+    return out