fix: organization user shouldn't be asked for payment for a premium username (#13535)

Co-authored-by: Joe Au-Yeung <65426560+joeauyeung@users.noreply.github.com>

packages/lib/server/username.ts

@@ -181,12 +181,11 @@ const usernameCheckForSignup = async ({
   const user = await prisma.user.findFirst({
     where: {
       email,
-      // Simply remove it when we drop organizationId column
-      organizationId: null,
     },
     select: {
       id: true,
       username: true,
+      organizationId: true,
     },
   });
 
@@ -206,13 +205,15 @@ const usernameCheckForSignup = async ({
 
     // When we invite an email, that doesn't match the orgAutoAcceptEmail, we create a user with organizationId=null.
     // The only way to differentiate b/w 'a new email that was invited to an Org' and 'a user that was created using regular signup' is to check if the user is a member of an org.
+    // If username is in global namespace
     if (!userIsAMemberOfAnOrg) {
       response.available = false;
+      // There are no premium users outside an organization only
+      response.premium = await isPremiumUserName(username);
     }
-  }
-
-  if (await isPremiumUserName(username)) {
-    response.premium = true;
+  } else {
+    // If user isn't found, it's a new signup and that can't be of an organization
+    response.premium = await isPremiumUserName(username);
   }
 
   // get list of similar usernames in the db