Add Grails 8 creating-your-first-grails-app guide.

[sanjana2505006]

Adds the Grails 8 creating-your-first-grails-app guide under guides/creating-your-first-grails-app/v8/ (AsciiDoc chapters + vendored snippets from complete/) and registers versions['8'] in conf/guides.yml.

Companion to grails-guides/creating-your-first-grails-app#65

[sanjana2505006]

@jamesfredley let me know if there's any scope for improvements

[sbglasius]

One minor issue

[sbglasius]

Why not mention url-mappings?

[sanjana2505006]

Added url-mappings to the v8 tags.
Thanks!

[sanjana2505006]

@jamesfredley Updated with the Asset Pipeline chapter as discussed

[jamesfredley]

Integration test fails. This is the real merge blocker.

Companion CI on the current head (1614c56) failed on the fork:

https://github.com/sanjana2505006/creating-your-first-grails-app/actions/runs/30950958344

Job	Result
initial unit tests	pass
complete unit tests	pass
complete integrationTest	fail
complete bootRun smoke	skipped because of the fail

The only spec:

@Integration
class HomePageSpec extends ContainerGebSpec {
    void 'home page lists seeded vehicles'() {
        when:
        go '/'
        then:
        title == 'Home Page'
        $('h1').text().contains('Welcome')
        $('li a', text: contains('Pickup')).size() == 1
    }
}

It never got as far as Geb. Spring failed to start the test context:

IllegalStateException
  Caused by: BadSqlGrammarException
    Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException

Likely cause: Vehicle has Integer year. H2 treats YEAR as a reserved word, so schema create during @Integration blows up. Unit tests do not hit a live H2 schema the same way, which is why they passed.

That matters because this guide tells readers to run ./gradlew integrationTest and includes this spec. If we merge both PRs as-is, the published beginner guide documents a command that fails on the companion sample.

No commit has been pushed since that 2026-08-04 failure.