feat: strategy builder

backend/main.py

@@ -68,6 +68,28 @@ app.add_middleware(
 )
 
 
+@app.exception_handler(Exception)
+async def _global_exception_handler(request, exc: Exception):
+    """Catches anything that slips past a route's own try/except (including errors
+    during response serialization, which happen after a handler already returned) —
+    without this, such errors surface as an opaque bare "Internal Server Error" with
+    no detail and nothing in System Logs. Every unhandled exception, anywhere in the
+    app, now gets a full traceback in System Logs and a real JSON detail in the response."""
+    import traceback
+    from fastapi.responses import JSONResponse
+    tb = traceback.format_exc()
+    try:
+        from services.database import log_system_event
+        log_system_event(
+            level="ERROR", source="unhandled_exception",
+            message=f"{request.method} {request.url.path}: {exc}",
+            details={"error": str(exc), "traceback": tb},
+        )
+    except Exception:
+        pass  # Never let logging failure mask the original error
+    return JSONResponse(status_code=500, content={"detail": f"Erreur interne: {exc} (voir System Logs)"})
+
+
 @app.on_event("startup")
 def startup():
     # Attach DB log handler to root logger (captures WARNING+ from all modules)