refactor: server-next -> server

packages/server/next/.gitignore

packages/server/next/.prettierrc.json

packages/server/next/app/favicon.ico

packages/server/next/app/globals.css

packages/server/next/app/layout.tsx

packages/server/next/app/page.tsx

packages/server/next/eslint.config.mjs

packages/server/next/index.ts

packages/server/next/next.config.ts

packages/server/next/postcss.config.mjs

packages/server/next/tsconfig.json

packages/server/package.json

packages/server/src/index.ts

packages/server/src/server.ts

packages/server/src/workflow/stream.ts

packages/server/src/workflow/tools.ts

packages/server/src/workflow/type.ts

packages/server/tsconfig.json

tsconfig.json