Implementation of Animal Companion, Construct, Familiar or Permanent Summon Slot

Hello, could you include a slot for each character to have a single permanent companion—such as a ranger’s animal companion, a golem, a familiar, or another permanent summon? This companion wouldn't require the full party mechanics like skill checks, but it should be able to interact with the narrative and combat. The companion should also be able to move seamlessly with the party. Thank you.