DiffDeck, a PR review tool with file context and code navigation

I built DiffDeck because I was struggling to review larger pull requests in GitHub, especially ones with a lot of AI-assisted code.

GitHub's diff view works well for smaller changes, but once a PR gets big I usually want more of an editor-style workflow while reviewing ie see the surrounding code, jump to related symbols and files, and mark off what I have already reviewed and I felt Github's interface was really frustrating me.

DiffDeck opens a GitHub pull request in a review workspace with:

- full file context - go-to-definition and references for TS/JS - review notes - per-file reviewed state and review progress - hide/checkoff reviewed files

One thing I wanted was for it to feel closer to VS Code than a traditional PR tool. You can jump around the codebase while reviewing, and features like go-to-definition are meant to feel familiar if you already spend most of your time in an editor.

Right now it requires GitHub sign-in, because the point is to open pull requests you already have access to and review them with more context than GitHub's diff view gives you. I considered making a public demo, but that felt less representative than letting people try it on their own PRs.

This is an early alpha. Right now the code navigation features are focused on TypeScript and JavaScript codebases. The main thing I'm trying to learn is whether this is actually a better review workflow than staying in GitHub's PR UI. For now you can feel free to review a single PR.

I'd especially like feedback from people who review large PRs or AI-generated code:

- what still feels missing - whether this solves a real problem or just one I personally had