make player and client bound together

this cleansup and allows rejoining a running server

crates/shared/src/protocol/mod.rs

@@ -189,3 +189,11 @@ impl TbMapIdCounter {
 #[derive(Resource, Reflect, Default, Deref, DerefMut)]
 #[reflect(Resource)]
 pub struct TbMapEntityMapping(pub HashMap<u64, Entity>);
+
+#[derive(Component)]
+#[relationship(relationship_target = ClientOwns)]
+pub struct OwnedByClient(pub Entity);
+
+#[derive(Component)]
+#[relationship_target(relationship = OwnedByClient, linked_spawn)]
+pub struct ClientOwns(Entity);