#4243: fix: resolve Node.js punycode deprecation warning

## Summary Fixes #4184 Resolves the Node.js punycode deprecation warning that appears in gateway logs. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR updates dependency resolution to eliminate the Node.js `punycode` deprecation warning seen in gateway logs by overriding `whatwg-url` to `7.1.0` (which uses the userland `punycode.js` implementation). It records the change in `CHANGELOG.md` and updates `pnpm-lock.yaml` accordingly (notably bumping `whatwg-url` and its transitive deps `tr46` and `webidl-conversions`). <h3>Confidence Score: 4/5</h3> - This PR is likely safe to merge; it’s a targeted dependency override with limited blast radius, but it changes URL parsing-related transitive deps so it warrants a quick smoke test in the gateway runtime. - Changes are confined to dependency metadata (package.json overrides + lockfile) and a changelog entry, with no application code modifications. The main risk is subtle behavior differences from the `whatwg-url`/`tr46`/`webidl-conversions` upgrades in codepaths that construct/parse URLs (e.g., node-fetch consumers). - package.json (overrides), pnpm-lock.yaml (transitive dependency upgrades) <!-- greptile_other_comments_section --> _{(4/5) You can add custom instructions or style guidelines for the agent [here](https://app.greptile.com/review/github)!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->