Refactor space admin permissions for member creation

Simplify access polices

Author: ymc9

zenstack/schema.zmodel

@@ -69,8 +69,8 @@ model SpaceUser {
     // space owner can add any one
     @@allow('create', space.owner == auth())
 
-    // space admin can add anyone but not himself
-    @@allow('create', auth() != user && space.members?[user == auth() && role == ADMIN])
+    // space admin can add new members
+    @@allow('create', space.members?[user == auth() && role == ADMIN])
 
     // space admin can update and delete
     @@allow('update,delete', space.members?[user == auth() && role == ADMIN])
@@ -182,4 +182,4 @@ model Account {
     session_state            String?
     user                     User    @relation(fields: [userId], references: [id], onDelete: Cascade)
     @@unique([provider, providerAccountId])
-}
+}