feat: initial dev-configs monorepo

Shared configs for TypeScript projects: ESLint, Prettier, TypeScript,
Vite, Jest, Playwright, Knip. Published as @vigdorov/* npm packages
to Gitea registry.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/vite/src/index.ts

@@ -0,0 +1,2 @@
+export {spa, type SpaOptions} from './spa.js';
+export {library, type LibraryOptions} from './library.js';