### Problem/Motivation Display Builder 1.0.0-beta10 prints the `[Page] Title` source as the title text only, no longer in `<h1 class="page-title">` ([#3621589](https://www.drupal.org/node/3621589)). Its release notes: "A page layout placing it straight in a slot loses its heading: put it in a heading component." The page layouts of the theme place it straight in a slot, so they lost their h1: - `config/optional/display_builder_page_layout.page_layout.webtheme_sign_in.yml`: the `title` slot of the *Sign in* component, which expects the heading (`page--sign-in.html.twig` passes a `page_title` element there). - `tests/fixtures/display_builder_page_layout.page_layout.webtheme_test_landmarks.yml`: the `content` slot of the main *Section*. The last green `12.0.x` pipeline resolved `drupal/display_builder` 1.0.0-beta9. The [pipeline](https://git.drupalcode.org/project/webtheme/-/pipelines/1039848) of !28, an unrelated test change, resolved 1.0.0-beta10 with every other package the same, and fails 6 of 116 scenarios, the same 6 on a retry: ``` 1) Scenario: The header and footer sections of a page layout are the banner and the contentinfo # tests/features/04-01-01-display-builder.feature:47 ✖ And the page should have exactly one h1 AssertionError [ERR_ASSERTION]: Expected 1 <h1>, found 0. 2) Scenario: The sign-in page layout draws the sign-in screens when the theme settings pick it # tests/features/04-01-01-display-builder.feature:60 ✖ And the page should have exactly one h1 AssertionError [ERR_ASSERTION]: Expected 1 <h1>, found 0. 3) Scenario: the front page passes the accessibility checks # tests/features/05-01-01-accessibility.feature:35 ✖ And the page should have exactly one h1 AssertionError [ERR_ASSERTION]: Expected 1 <h1>, found 0. 4) Scenario: the login page passes the accessibility checks # tests/features/05-01-01-accessibility.feature:36 ✖ And the page should have exactly one h1 AssertionError [ERR_ASSERTION]: Expected 1 <h1>, found 0. 5) Scenario: the password reset page passes the accessibility checks # tests/features/05-01-01-accessibility.feature:37 ✖ And the page should have exactly one h1 AssertionError [ERR_ASSERTION]: Expected 1 <h1>, found 0. 6) Scenario: The offcanvas menu of / is used with the keyboard only # tests/features/05-02-01-wcag-aaa.feature:86 ✖ And I press the key "Tab" until ".uk-navbar-toggle" has the focus AssertionError [ERR_ASSERTION]: ".uk-navbar-toggle" did not get the focus after 80 presses of Tab. 116 scenarios (6 failed, 9 skipped, 101 passed) 1023 steps (6 failed, 148 skipped, 869 passed) ``` Scenarios 1 and 2 are the bug. Their clean-up steps are then skipped: the test layout (path `/node`, the front page) and the sign-in layout stay on and draw `/`, `/user/login` and `/user/password` for scenarios 3 to 6: no h1, and no navbar toggle on `/`. Environment: Drupal 11.4.9, PHP 8.4, MySQL (drupalci), Display Builder 1.0.0-beta10, UI Patterns 2.0.23, Chrome for Testing 158 (Playwright). #### Steps to reproduce ``` Given Webtheme is the default theme, with the page layouts of Display Builder 1.0.0-beta10 And the "Sign-in screens" page layout is picked in the sign-in settings of the theme When an anonymous user goes to /user/login Then the page has no h1: "Log in" is plain text in the card ``` ### Proposed resolution As the release notes say, put the page title in the *Heading* component, level 1: 1. `webtheme_sign_in`: `webtheme:heading` (`heading_level: 1`) in the `title` slot of `webtheme:sign_in`, the page title in its `title` slot. `.webtheme-sign-in__title > *` styles it as before. 2. The landmarks fixture: the same heading in the main section. 3. A post update: an installed `webtheme_sign_in` with the page title straight in `title` gets the heading. 4. `composer.json` conflicts with `drupal/display_builder` before 1.0.0-beta10, whose page title prints its own h1: the heading would nest a second one. 5. README: how a page layout places the page title. AI-Generated: Yes (fix; reviewed by Rajab Natshah.) ### Checkpoints - [x] File an issue - [x] Fix bugs in code - [x] Testing to ensure no regression - [x] Automated unit testing coverage - [x] Automated functional testing coverage - [ ] UX/UI designer responsibilities - [ ] Readability - [x] Accessibility - [ ] Performance - [ ] Security - [x] Documentation - [ ] Reviewed by human - [ ] Code review by maintainers - [ ] Full testing and approval - [ ] Credit contributors - [ ] Review with the product owner - [x] Release Notes - [x] Release ### API changes None. ### Data model changes None. ### Release notes snippet