chore: replace "manager role" with "administrator role" (#11395)

# Which Problems Are Solved

As part of the naming consistency initiative, the term `Manager Roles`
is replaced by `Administrator Roles`

# How the Problems Are Solved

By replacing `Manager Roles` with `Administrator Roles` in API docs,
Console UI, and guides.

# Additional Changes
N/A

# Additional Context
- Closes https://github.com/zitadel/zitadel/issues/11293

---------

Co-authored-by: Copilot <[email protected]>

docs/docs/examples/login/nextjs-b2b.md

@@ -138,12 +138,12 @@ Let's call this new organization `Demo-Customer`.
 Now switch back to the organization `Demo-Customer` and [create a new user](/guides/manage/console/users-overview#create-user) in this organization.
 Let's call the first user `Alice Admin`. Create a second user called `Eric Employee`.
 
-### Manager Role
+### Administrator Role
 
 We want to enable Alice to assign roles to users in her organization in a self-service manner.
-To make this happen, we need give Alice an [Manager Role](/concepts/structure/managers) within the Organization `Demo-Customer`.
+To make this happen, we need to assign Alice an [Administrator Role](/concepts/structure/managers) within the Organization `Demo-Customer`.
 
-Still in the organization `Demo-Customer`, navigate to Organization. Click on the plus on the top right and give `Alice Admin` the Manager Role `Org Owner`.
+Still in the organization `Demo-Customer`, navigate to Organization. Click on the plus on the top right and give `Alice Admin` the Administrator Role `Org Owner`.
 
 Login with your user on the customer organization to validate the setup.