(core) show any error when creating initial team site with GRIST_SINGLE_ORG

Summary: Also clarifies that only lowercase letters are accepted.

Test Plan: manual

Reviewers: jarek

Reviewed By: jarek

Subscribers: jarek

Differential Revision: https://phab.getgrist.com/D3647

app/server/companion.ts

@@ -80,14 +80,14 @@ export function addSiteCommand(program: commander.Command,
         // This should not happen.
         throw new Error('failed to create user');
       }
-      await db.addOrg(user, {
+      db.unwrapQueryResult(await db.addOrg(user, {
         name: domain,
         domain,
       }, {
         setUserAsOwner: false,
         useNewPlan: true,
         planType: 'teamFree'
-      });
+      }));
     });
 }