Add a default recipe with the AI modules and providers

Problem/Motivation

Web AI has no code yet. The Webship site templates have no AI, and every site that wants it has to pick the AI modules and providers, install them and choose a default provider by hand.

Steps to reproduce

1. Install a Webship site template.
2. Look for the AI module and a provider: nothing is installed.

Proposed resolution

• Add a recipes/default recipe, like the other web* modules, applied by hook_install().
• Install the AI module with the submodules an editorial site uses, plus AI Agents and AI Image Alt Text.
• Install five providers: Anthropic, OpenAI, Gemini, xAI (Grok) and Huggingface.
• Set Anthropic as the default provider, with a sensible default model.
• Leave every API key unset: keys are site owner data.
• Require Display Builder AI, AI Penpot and AI Playwright so they are available, and leave them uninstalled.

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ❌ Code review by maintainers

User interface changes

The AI settings and provider settings pages are available after the install.

API changes

None.

Data model changes

None.

Version: 12.0.x-dev

AI-Generated: Yes