Grails 7 - grails-spring-security Doc - default approch

### Expected Behavior

grails-spring-security is using pessimistic approach **by default** as it says in section `4.1. Pessimistic Lockdown`. Which is true I have tested it.

### Actual Behaviour

But grails-spring-security Doc section 1.1.3, presumes Public approach **by default**. Methods in Controller should be lockdown by `@Secured(['ROLE_USER'])`

### Steps To Reproduce

See section 1.1.3 and 4.1 of [Spring Security Core Plugin - Reference Documentation](https://apache.github.io/grails-spring-security/7.0.x/core-plugin/guide/index.html#gettingStarted)

### Environment Information

java=21.0.8-zulu
gradle=8.14.3
groovy=4.0.28
grails=7.0.0-RC2

### Example Application

_No response_

### Version

7

Start with sections 1.1.3 and 4.1 of the linked Spring Security Core Plugin Reference Documentation and compare their statements about the default approach. Reconcile the documentation so it consistently describes the actual default behavior, then verify both sections no longer contradict each other.

Written by the indexing model from the issue text.