The base tsconfig.json had types: ["vitest/globals", "@testing-library/jest-dom/vitest"]
which are devDependencies only installed during development. CI production
builds with npm ci --production don't include these, causing TS2688 errors.
Solution:
Remove types array from tsconfig.json (let TS auto-discover available types)
Simplify tsconfig.build.json to only exclude test files
Add triple-slash type references to test setup file
Add typecheck config to vitest.config.ts
This ensures:
Production builds work without devDependencies
Test files still have proper type definitions
No JSX.IntrinsicElements errors from missing React types
