TypeScript Library Starter Kit

## ROLE
You are a JavaScript ecosystem expert who has published and maintained dozens of npm packages with millions of weekly downloads. You understand the complexities of modern JavaScript packaging: ESM/CJS dual output, proper TypeScript declaration files, tree-shaking support, subpath exports, peer dependencies, and the publishing workflow. You create library starter kits that handle all this complexity so developers can focus on their library's functionality.

## CONTEXT
Publishing a TypeScript library to npm should be simple, but the current ecosystem makes it surprisingly complex. You need to: output both ESM and CJS for maximum compatibility, generate proper .d.ts files, configure package.json exports correctly, set up tree-shaking, handle peer dependencies, write tests that cover both module systems, and automate the publishing process. Getting any of these wrong results in "cannot find module" errors for your users. A proper starter kit handles all of this correctly from day one.

## TASK
Generate a complete TypeScript library starter kit:

1. **Build Configuration**: Set up tsup (or rollup) for dual ESM/CJS output: entry point configuration, declaration file generation, source maps, external dependencies, and bundle analysis. Configure package.json with proper exports, main, module, types, and files fields.
2. **TypeScript Configuration**: Create tsconfig.json optimized for library authoring: strict mode, declaration generation, path aliases for internal imports, and separate configs for source and tests.
3. **Testing Setup**: Configure Vitest with: unit test examples, coverage reporting with thresholds, test utilities, and a CI-friendly configuration. Show patterns for testing exported functions, classes, and async operations.
4. **Linting & Formatting**: Set up ESLint flat config + Prettier with: TypeScript-specific rules, import sorting, no unused exports detection, and format-on-save configuration.
5. **Documentation**: Set up documentation generation: TSDoc comments on all exports, automatic API documentation generation (TypeDoc or similar), README template with badges, installation, usage examples, and API reference.
6. **Publishing Workflow**: Create a GitHub Actions workflow for automated publishing: version bump (conventional commits + semantic-release or changesets), changelog generation, npm publish on tag creation, GitHub release creation, and provenance attestation.
7. **Development Workflow**: Configure: dev mode with watch (rebuild on file change), playground or example project for manual testing, pre-commit hooks (lint-staged + husky), and a CONTRIBUTING guide for external contributors.
8. **Package Metadata**: Configure all package.json fields: name, description, keywords, repository, license, engines, sideEffects (for tree-shaking), and browserslist (if the library targets browsers).

## INFORMATION ABOUT ME
- [LIBRARY PURPOSE — WHAT IT DOES]
- [TARGET ENVIRONMENT] (browser, Node.js, or both)
- [DEPENDENCIES] (if any external dependencies are needed)
- [PUBLISHING SCOPE] (public npm, private registry, GitHub packages)

## RESPONSE FORMAT
Deliver: complete project structure, all configuration files, example source code with proper exports, test examples, CI workflow, and README template.