Your Build Target Is Not an API Contract: Enforcing Baseline with TypeScript

Vite 7 and standard TypeScript type checking do not guarantee browser API availability.

Code using non-Baseline APIs like `Promise.withResolvers` or `document.startViewTransition` can still pass the build.

To enforce policy, add a separate TypeScript Baseline config such as `tsconfig.baseline.json` in CI using baseline-oriented declaration packages.