tsup build + subpath exports + publish config

[qantrepreneur]

What to build

Set up the build and publish pipeline for @sundayceo/framework. The package uses tsup to compile TypeScript to ESM and generate declaration files, with subpath exports for the main entry and the Vite plugin.

Configure:

• tsup.config.ts with two entry points: src/core/index.ts and src/vite/index.ts
• ESM output only (no CJS — modern Node/Vite ecosystem)
• Declaration file generation (.d.ts)
• package.json exports map:
  • "." → core runtime
  • "./vite" → Vite plugin
• peerDependencies for react, react-dom, vite
• files field to control what gets published
• Verify the built package works: import from both entry points in a test consumer

Acceptance criteria

• tsup.config.ts builds both entry points
• ESM output with .d.ts declaration files
• package.json has correct exports map for . and ./vite
• peerDependencies declared for react, react-dom, vite
• files field excludes tests, playground, configs
• pnpm run build in packages/framework succeeds
• Built output is importable from both subpaths
• npm pack --dry-run shows correct file list

Blocked by

• Playground: app.ts + first template + static page #25