Moving Through and Sharing an Ally's Space
Mistveil → Rules → Moving Through and Sharing an Ally's Space
Outside of Initiative, movement through an ally's space costs no extra movement if they allow you to pass but you cannot end your movement on their space.
While in Initiative order, moving through an ally's space counts as difficult terrain and follows all appropriate rules and interactions.
No change to sharing space with an Ally, it is not allowed.
"Ending Your Movement: You can’t end your movement in the same square as another creature unless it is helpless. (Core Rulebook, Pg. 193)"