fix: improve agent response output in LangChain example

feat: add agent-with-tools example using Vercel AI SDK

feat: add Vercel AI SDK dependencies

feat: add agent-with-tools example using LangChain

chore: scope TypeScript include to src directory

feat: add LangChain, OpenAI, and Zod dependencies

chore: add bunfig.toml with exact versioning and isolated linker

chore: pin dependency versions to exact releases

fix: add missing newline at end of index.ts

chore: tighten tsconfig compiler options for stricter type safety

chore: initialize Bun project scaffold