Deliver the CoreAI starter for Replica #139

Outcome

Allow prototype authors to select a working CoreAI Sandbox without inheriting another starter's router, design system, or product assumptions.

Completed scope

• Add the CoreAI React Router Sandbox with CoreAI components, a Foundry-style shell, mock data, and app-specific agent guidance.
• Expose starter selection through the catalog and installer while preserving Minimal as the default.
• Include the shared Replica tooling and public Markdown documentation discovery workflow.
• Create an initial local Git commit so the generated repository supports worktree-based sessions.

Evidence

#64, authored by arniebradfo and merged October 26, 2026 (Pacific).

This closes the merged starter-delivery scope, not every onboarding or deployment concern. The separate canvas hydration/global-CSS defect remains tracked at #65.

Post-work issue: created retroactively to document already-completed work.