feat(js): support socks proxy

[barjin]

Enables support for socks proxies to impit-node. This theoretically enables socks proxies for CLI and the Python binding as well, but this behaviour is untested due to a lack of working socks proxy server implementations in Python.

[Copilot]

Pull Request Overview

This PR adds SOCKS proxy support to both the Rust core (impit) and the Node binding (impit-node), and includes a basic end‐to‐end test for the new feature.

• Enabled the socks feature in reqwest for Rust proxy support
• Added socksv5 dependency and SOCKS server setup in the Node tests
• Introduced a new supports socks proxy test in basics.test.ts

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

File	Description
impit/Cargo.toml	Enabled the socks feature flag for the reqwest crate
impit-node/package.json	Added socksv5 as a development/test dependency
impit-node/test/basics.test.ts	Imported and started a SOCKS server; added new test case

Comments suppressed due to low confidence (2)

impit-node/test/basics.test.ts:131

• [nitpick] For consistency with other tests prefixed by impit, consider renaming this test to impit supports socks proxy.

test('supports socks proxy', async (t) => {

impit/Cargo.toml:15

• [nitpick] While the Rust client now supports SOCKS, there are no integration tests verifying proxy usage on the Rust side. Consider adding a minimal end-to-end test to cover the new feature.

reqwest = { version = "0.12.9", features = ["json", "gzip", "brotli", "zstd", "deflate", "rustls-tls", "http3", "cookies", "stream", "socks"] }