feat(portfolio): portfolios.yml + load_active_portfolio (override operativi)

src/portfolio/base.py

@@ -77,3 +77,18 @@ class Portfolio:
         risk = {sid: float(rc[k] / pv * 100) if pv > 0 else 0.0
                 for k, sid in enumerate(self.sleeve_ids)}
         return PortfolioResult(self.code, w, full, oos, yearly_returns(port_dr), risk)
+
+
+def load_active_portfolio(config_path) -> "Portfolio":
+    """Carica il portafoglio attivo da portfolios.yml applicando gli override."""
+    import yaml
+    from pathlib import Path
+    from scripts.portfolios._defs import PORTFOLIOS
+
+    cfg = yaml.safe_load(Path(config_path).read_text())
+    p = PORTFOLIOS[cfg["active"]]
+    ov = cfg.get("overrides", {})
+    for k in ("total_capital", "weighting", "caps", "leverage", "rebalance", "vol_lookback"):
+        if k in ov and ov[k] is not None:
+            setattr(p, k, ov[k])
+    return p