Add the AI Translation Management (TMGMT) module to the Varbase Internationalization Base recipe

Problem/Motivation

A multilingual Varbase site that wants machine translation has to add an AI translation provider to its own composer.json today. Varbase Internationalization Base 1.0.0-rc2 already ships the Translation Management Tool (TMGMT) in the codebase without enabling it. The same pattern should cover AI machine translation, so a site can turn it on with one drush en instead of a Composer change.

Steps to reproduce

1. Install Varbase 11 (Drupal ~11.4) and apply the Varbase Internationalization Base 1.0.0-rc2 recipe.
2. Add a second language, then enable the translation jobs UI: drush en tmgmt tmgmt_content tmgmt_config tmgmt_local.
3. Go to Translation → Providers (/admin/tmgmt/translators) and try to add an AI translation provider.
4. There is none to add. The site has to require an AI translation provider in its own composer.json first.

Proposed resolution

• composer.json: require drupal/ai_tmgmt at ~1, listed directly under its parent drupal/tmgmt, and add the AI translation keyword.
• README.md: document the translation toolkit the recipe ships without enabling any of it — TMGMT (drush en tmgmt tmgmt_content tmgmt_config tmgmt_local) and AI Translation Management (drush en ai_tmgmt, which needs an AI provider and model configured first). Also state that the core Translate tab reaches a Drupal Canvas page's title, URL alias, description and metatags only, so translating the copy inside components is done through a TMGMT job.
• CHANGELOG.md: Unreleased entry.

The require block becomes:

"drupal/core": "~11.4.0",
"drupal/eca": "~3",
"drupal/tmgmt": "~1",
"drupal/ai_tmgmt": "~1"

Facts worth stating plainly before this is committed:

• AI Translation Management (TMGMT) has no stable release; the newest is 1.0.0-beta6. The bare-major ~1 constraint still resolves to it, verified with a real composer require --dry-run on a Varbase 11 project, because Varbase project roots run minimum-stability: dev with prefer-stable: true.
• It requires drupal/ai ^1.0.4 and drupal/tmgmt ^1.16, so applying this recipe brings the Drupal AI module into the codebase even on a site that uses no AI features.
• The recipe does not enable ai_tmgmt, and configures no API key, provider or model. It does nothing at all until a site configures an AI provider and model.
• Precedent: on a Varbase 11 sandbox environment, AI Translation Management 1.0.0-beta6 with AI Translate was wired as a TMGMT provider and proven end to end (a media field translated to French and accepted). That was done per environment on a branch, not in a recipe.

Testing so far: the project pipeline is green locally on both jobs, build:composer-validate and validate:yaml-lint. A functional install test on a Varbase 11 site confirmed drupal/ai_tmgmt resolves to 1.0.0-beta6, ships on disk unenabled, and enables cleanly with no watchdog errors. No AI provider or API key was configured, so the provider translation path itself is unproven.

Remaining tasks

• ✅ File an issue
• ✅ Addition/Change/Update/Fix
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support
• ➖ User Guide Documentation support
• ➖ 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 varbase-11.0.0, varbase_i18n_base-1.0.0-rc3

User interface changes

• None. Nothing is enabled, so no screen changes until a site runs drush en ai_tmgmt.

API changes

• None.

Data model changes

• None. No configuration is added or altered by the recipe.

Release notes snippet

• Added the AI Translation Management (TMGMT) module (drupal/ai_tmgmt ~1) to the codebase without enabling it, so a site can turn on AI machine translation as a Translation Management Tool provider with drush en ai_tmgmt once an AI provider and model are configured.