Apply the Varbase AI Context and Varbase AI Safety recipes with the Varbase AI Base recipe

Problem/Motivation

Varbase AI Base requires varbase_ai_context and varbase_ai_safety but does not apply them: neither is in recipes: in recipe.yml. A site that applies the base gets:

• no starter context items (brand, editorial rules, safety guardrails), and max_global_items stays at 3 instead of 10
• no guardrails, no AI Logging and no AI Observability

The maintainers decided both should apply by default. They were added as optional recipes in #3589355: Add Varbase AI Context recipe as an optional recipe to Varbase AI Base recipe and #3589356: Add Varbase AI Safety recipe as an optional recipe to Varbase AI Base recipe.

Steps to reproduce

1. Apply Varbase AI Base on a fresh Varbase 11 site.
2. Look for the starter context items and the AI guardrails. None exist.

Proposed resolution

1. Add varbase_ai_context, then varbase_ai_safety last, to recipes:.
2. Make the README sub-recipe list match recipes: (it still names varbase_ai_default) and note that Safety needs a default AI chat model.
3. Add a CHANGELOG entry under Unreleased. No version bump.

Tested in the MR: without a default chat model, the Prompt Safety sub-recipe of Safety stops the base recipe with "does not have a default model". Both recipes are applied by default as decided, and the README and the 1.0.1 release notes state the requirement.

AI-Generated: Yes

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_ai_base-1.0.1

User interface changes

• N/A

API changes

• N/A

Data model changes

• Sites applying the base gain three starter context items (Draft and unpublished on a clean install), 14 guardrails in 3 sets, and AI Logging and AI Observability.
• max_global_items becomes 10.

Release notes snippet

• Varbase AI Base now also applies Varbase AI Context and Varbase AI Safety.