feat(deps): add undici dependency version 8.4.1

[TAYUN]

Summary

Add undici@8.4.1 as an explicit dependency.

Why

This project uses Agent, ProxyAgent, and setGlobalDispatcher from undici in the proxy setup logic.

According to the Undici documentation, these APIs are not provided by Node.js built-in fetch alone. Built-in fetch covers the standard request interface, but advanced networking features such as ProxyAgent, Socks5Agent, and MockAgent require the undici package directly.

Since OpenCommit uses ProxyAgent and setGlobalDispatcher to configure proxy behavior, undici should be declared explicitly in dependencies.

https://github.com/nodejs/undici

Changes

• add undici@8.4.1 to dependencies

Verification

• confirmed src/utils/proxy.ts imports and uses Agent, ProxyAgent, and setGlobalDispatcher from undici
• confirmed pnpm build succeeds after adding the dependency