feat: #3619859 Install the Canvas Translate module by default

Issue: #3619859 Install the Canvas Translate module by default

What this changes

• recipe.yml: adds canvas_translate to install:, right after content_translation.
• composer.json: adds drupal/canvas_translate: ~1 to require.
• recipe.yml: grants translate canvas content to Content Editor, Content Admin, SEO Admin and Site Admin, the same four roles this recipe already gives the other translation permissions to.

Why

Canvas Translate is what lets an editor translate a Canvas page's component tree. This recipe already makes canvas_page translatable and marks the components base field translatable, so the translation UI for it is the missing piece.

Maintainer decision needed: alpha dependency

canvas_translate is currently at 1.0.0-alpha4. Under the Varbase project's minimum-stability: dev + prefer-stable: true, ~1 resolves to that alpha (verified in a clean sandbox). Installing an alpha module by default in a distribution recipe is an explicit maintainer call, not something this MR settles.

For context: #3588171 added a different Canvas-multilingual module (canvas_multilingual) to this recipe and it was reverted, so the caution here is not theoretical.

Upstream issues found while testing this on plain Drupal 11.4

• #3619868, filed by us: installing Canvas Multilingual onto a site that already has Canvas Translate is not guarded. #3612081 guards only the opposite order, and the existing guard is bypassable with drush -y, so scripted builds and recipes can reach the unsupported state.
• #3617651, pre-existing upstream, Major, Needs work: translating a rich text prop silently deletes markup. Not filed by us; referenced here because it is open against the version this recipe now installs by default.

For the record: canvas_translate is at 1.0.0-alpha4, drupal.org reports no usage statistics for it, and a different Canvas multilingual module (canvas_multilingual) was previously added to this same recipe and then reverted (#3588171).

AI-Generated: Yes

Checkpoints

• File an issue about this project
• Addition/Change/Update/Fix to this project
• Testing to ensure no regression
• Automated unit/functional testing coverage
• Developer Documentation support on feature change/addition
• User Guide Documentation support on feature change/addition
• UX/UI designer responsibilities
• Accessibility and Readability
• Reviewed by a human
• Code review by maintainers
• Full testing and approval
• Credit contributors
• Review with the product owner
• Update Release Notes
• Release