fix: redesign relative rotation for multi-symbol comparison

- Accept comma-separated symbols query param instead of single path param
- Move endpoint from /stock/{symbol}/technical/relative-rotation to
  /technical/relative-rotation?symbols=AAPL,MSFT,GOOGL&benchmark=SPY
- Fetch all symbols + benchmark in single obb.equity.price.historical call
- Add RRG quadrant classification (Leading/Weakening/Lagging/Improving)
- Support study parameter (price/volume/volatility)

routes_technical.py

@@ -164,14 +164,23 @@ async def stock_vwap(symbol: str = Path(..., min_length=1, max_length=20)):
     return ApiResponse(data=data)
 
 
-@router.get("/stock/{symbol}/technical/relative-rotation", response_model=ApiResponse)
+@router.get("/technical/relative-rotation", response_model=ApiResponse)
 @safe
-async def stock_relative_rotation(
-    symbol: str = Path(..., min_length=1, max_length=20),
+async def relative_rotation(
+    symbols: str = Query(..., min_length=1, max_length=200, description="Comma-separated symbols, e.g. AAPL,MSFT,GOOGL"),
     benchmark: str = Query(default="SPY", min_length=1, max_length=20),
+    study: str = Query(default="price", pattern="^(price|volume|volatility)$"),
 ):
-    """Relative Rotation -- strength vs benchmark (sector rotation analysis)."""
-    symbol = validate_symbol(symbol)
+    """Relative Rotation Graph -- compare multiple symbols vs benchmark.
+
+    Returns RS-Ratio and RS-Momentum for each symbol, indicating
+    RRG quadrant: Leading, Weakening, Lagging, or Improving.
+    """
+    symbol_list = [validate_symbol(s.strip()) for s in symbols.split(",") if s.strip()]
+    if not symbol_list:
+        return ApiResponse(data=[], error="No valid symbols provided")
     benchmark = validate_symbol(benchmark)
-    data = await technical_service.get_relative_rotation(symbol, benchmark=benchmark)
+    data = await technical_service.get_relative_rotation(
+        symbol_list, benchmark=benchmark, study=study,
+    )
     return ApiResponse(data=data)