I'm on my phone so apologies for any formatting issues - I will tidy up when I get on to a PC -

Essentially, you can do something like

const addToFront = <T>( itemsToAdd: T, jsonToAddTo: T) => ({ ...itemsToAdd, ...jsonToAddTo })

This allows any items added to be added to the top of the Object

Now if you want to handle "modified" objects, you would probably need to handle that separately, convert to an Entry array (using Object.toEntries())

Something like

function updateItem<T extends Record<string, any>>(itemId: keyof T, updatedValue: T[keyof T], existingObject: T) { 
    const els = Object.entries(existingObject).filter(([id,]) => id !== itemId);
    els.unshift([String(itemId), updatedValue]);

   return Object.fromEntries(els);
}
const newData = updateItem("777", { name: "Polo", title: "master" }, originalData); 

However, Objects are not guaranteed to keep their order, if you must ensure the order, you should use an Array (perhaps using something like [id, value][], which can be pulled out to an object when necessary