Improve error messages from server actions in 6-server.js

[avinxshKD]

The error handling in src/graph-builder/graph-core/6-server.js is pretty bare-bones right now. All the server actions (build, debug, run, clear, stop, destroy, library) just do:

.catch((err) => {
    toast.error(err.message);
    toast.dismiss(toastId);
});

So when the backend returns something useful like "Invalid workflow file" or "Permission denied", users just see "Request failed with status code 500" or "Network Error".

Compare this to ContributeDetails.jsx which actually checks the response:

catch (error) {
    if (error?.response?.status === 400) {
        toast.info(error?.response?.data?.message);
    } else {
        toast.error(error?.response.data.message);
    }
}

We should update all those catch blocks to look for err.response?.data?.message first before falling back to err.message. Makes debugging way easier for userss

[avinxshKD]

working on the fix @pradeeban let me knw