Implement a Compose function that draws objects on screen and retains them across orientation change (remember, rememberSaveable, custom Saver).
Asked in the Round 2: Coding Android stage. For grading, model the state layer as a pure function: use saved_state when available, otherwise use the current objects, and return the ordered objects that should be rendered.
objects and saved_state are lists of drawable dictionaries with id, type, x, y, and color. Return a new list without mutating either input. A custom Saver must preserve every field.
def compose_canvas(objects, saved_state):