feat: strategy builder

backend/routers/strategy_builder.py

@@ -147,8 +147,6 @@ def optimize(req: OptimizeRequest):
             objective=req.constraints.objective,
             top_n=req.constraints.top_n,
         )
-    except ValueError as e:
-        raise HTTPException(status_code=404, detail=str(e))
     except Exception as e:
         import traceback
         from services.database import log_system_event
@@ -158,7 +156,8 @@ def optimize(req: OptimizeRequest):
             message=f"Optimize failed for {req.scenario.symbol}: {e}",
             ticker=req.scenario.symbol, details={"error": str(e), "traceback": tb},
         )
-        raise HTTPException(status_code=500, detail=f"Erreur optimiseur: {e} (détail complet dans System Logs)")
+        status = 404 if isinstance(e, ValueError) else 500
+        raise HTTPException(status_code=status, detail=f"{e}")
     return results