Link to service accounts from a few more places

Author: pjlast

docs/admin/auth/index.mdx

@@ -29,6 +29,10 @@ The following methods are supported for sign up and sign in:
 
 The authentication providers are configured in the [`auth.providers`](/admin/config/site_config#authentication-providers) site configuration option.
 
+## Programmatic authentication
+
+For automated systems, CI/CD pipelines, and API integrations that need to authenticate without human interaction, use [service accounts](/admin/access_control/service_accounts). Service accounts are specialized user accounts designed for automation that authenticate using access tokens rather than passwords.
+
 ## Login form configuration
 
 To configure the presentation of the login form, see the [login form configuration page](/admin/auth/login_form).

docs/api/graphql/index.mdx

@@ -32,6 +32,8 @@ You should see a response like this:
 { "data": { "currentUser": { "username": "YOUR_USERNAME" } } }
 ```
 
+For automated scripts, CI/CD pipelines, and production integrations, use [service accounts](/admin/access_control/service_accounts) instead of personal access tokens. Service accounts are designed specifically for programmatic API access and provide better security and audit capabilities.
+
 ## Documentation & tooling
 
 ### API Console