feat: strategy builder

backend/services/database.py

@@ -3159,6 +3159,22 @@ def get_iv_history(ticker: str, days: int = 90) -> List[Dict]:
     return [dict(r) for r in rows]
 
 
+def get_iv_change_1d(ticker: str, current_iv: float) -> Optional[float]:
+    """Day-over-day IV delta (decimal, e.g. 0.012 = +1.2 vol points) — current_iv minus
+    the most recent prior trading day's recorded iv_current. None if no prior day exists."""
+    conn = get_conn()
+    row = conn.execute(
+        """SELECT iv_current FROM iv_history
+           WHERE ticker=? AND iv_current IS NOT NULL AND recorded_date < date('now')
+           ORDER BY recorded_date DESC LIMIT 1""",
+        (ticker.upper(),),
+    ).fetchone()
+    conn.close()
+    if not row or row["iv_current"] is None:
+        return None
+    return current_iv - row["iv_current"]
+
+
 # ── IV Watchlist ──────────────────────────────────────────────────────────────
 
 def get_watchlist_tickers() -> List[str]: