feat: integration tests, seed data, and smoke test script

Add integration tests for the news pipeline (test_news_pipeline.py) and
trading flow (test_trading_flow.py) using real Redis with mocked FinBERT
and Alpaca. Add seed_strategies.py to insert default strategies (momentum,
mean_reversion, news_driven) with equal weights. Add smoke_test.sh for
end-to-end stack validation. Update pyproject.toml with integration marker
and scripts package discovery.

scripts/seed_strategies.py

@@ -0,0 +1,109 @@
+"""Seed default trading strategies.
+
+Inserts three strategies with equal initial weights (0.333 each):
+  - momentum
+  - mean_reversion
+  - news_driven
+
+Usage:
+    python -m scripts.seed_strategies
+"""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+
+from sqlalchemy import select
+
+from shared.config import BaseConfig
+from shared.db import create_db
+from shared.models.trading import Strategy
+
+logger = logging.getLogger(__name__)
+
+# Default strategies to seed
+DEFAULT_STRATEGIES = [
+    {
+        "name": "momentum",
+        "description": (
+            "Buy when price crosses above N-period SMA with increasing volume; "
+            "sell when it crosses below."
+        ),
+        "current_weight": 0.333,
+        "active": True,
+    },
+    {
+        "name": "mean_reversion",
+        "description": (
+            "Buy when RSI < 30 (oversold); sell when RSI > 70 (overbought). "
+            "Signal strength proportional to RSI extremity."
+        ),
+        "current_weight": 0.333,
+        "active": True,
+    },
+    {
+        "name": "news_driven",
+        "description": (
+            "Buy on strong positive sentiment (score > 0.7, confidence > 0.6); "
+            "sell on strong negative. Decay factor for stale news (> 4 hours)."
+        ),
+        "current_weight": 0.333,
+        "active": True,
+    },
+]
+
+
+async def seed(database_url: str | None = None) -> None:
+    """Insert default strategies if they do not already exist.
+
+    Parameters
+    ----------
+    database_url:
+        Override for the database URL.  If ``None``, the default from
+        :class:`~shared.config.BaseConfig` is used.
+    """
+    config = BaseConfig()
+    if database_url:
+        config.database_url = database_url
+
+    _engine, session_factory = create_db(config)
+
+    async with session_factory() as session:
+        for strategy_data in DEFAULT_STRATEGIES:
+            # Check if the strategy already exists by name
+            result = await session.execute(
+                select(Strategy).where(Strategy.name == strategy_data["name"])
+            )
+            existing = result.scalar_one_or_none()
+
+            if existing:
+                logger.info(
+                    "Strategy '%s' already exists (weight=%.3f), skipping",
+                    existing.name,
+                    existing.current_weight,
+                )
+                continue
+
+            strategy = Strategy(**strategy_data)
+            session.add(strategy)
+            logger.info(
+                "Inserted strategy '%s' with weight %.3f",
+                strategy_data["name"],
+                strategy_data["current_weight"],
+            )
+
+        await session.commit()
+
+    await _engine.dispose()
+    logger.info("Strategy seeding complete")
+
+
+def main() -> None:
+    """CLI entry-point."""
+    logging.basicConfig(level=logging.INFO)
+    asyncio.run(seed())
+
+
+if __name__ == "__main__":
+    main()