fix: catch all pipeline errors, add cost to response

app.py

@@ -44,6 +44,7 @@ class QueryResponse(BaseModel):
     complexity: Optional[dict] = None
     retrieval_source: Optional[str] = None
     cost: Optional[dict] = None
+    cost: Optional[dict] = None
 
 @app.get("/")
 def root(): return {"status": "ACRA API is live \U0001F680", "docs": "/docs"}