Add `as const` to vite.config.ts treeshake block: TypeScript 6 no longer widens `false` literals to `boolean` in object literals contextually typed against a union, so the explicit assertion is needed to satisfy Rollup's TreeshakingOptions. Note: vite-plugin-dts still uses a bundled TypeScript 5.9.3 (API Extractor); build output is correct but the warning will clear once vite-plugin-dts ships a TS6-aware release. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Signed-off-by: Vaclav Vancura <commit@vancura.dev>