Resetting the Orbital Sim should return the orbits to their starting positions

Currently, if you click the `Reset` button in the Orbital Sim it will only reset the time, not the positions of the orbits.

When clicking the `Reset` button the positions of the orbits should reset to their original starting positions.

Start at the Orbital Sim implementation and trace the `Reset` button handler, focusing on how it resets time versus orbit positions. Update the reset behavior so both time and positions return to their original starting values, then verify the simulation after advancing and clicking `Reset`.

Written by the indexing model from the issue text.