feat: signal generator — weighted ensemble with market data

shared/strategies/base.py

@@ -0,0 +1,26 @@
+"""Abstract base class for trading strategies."""
+
+from abc import ABC, abstractmethod
+
+from shared.schemas.trading import MarketSnapshot, SentimentContext, TradeSignal
+
+
+class BaseStrategy(ABC):
+    """Interface that every trading strategy must implement.
+
+    Each strategy evaluates market conditions (and optionally sentiment)
+    for a given ticker and returns a ``TradeSignal`` if the strategy has
+    an opinion, or ``None`` if it is neutral.
+    """
+
+    name: str
+
+    @abstractmethod
+    async def evaluate(
+        self,
+        ticker: str,
+        market: MarketSnapshot,
+        sentiment: SentimentContext | None = None,
+    ) -> TradeSignal | None:
+        """Return a signal if this strategy has an opinion, ``None`` otherwise."""
+        ...