Everyone talks badly about Cursor and it is kinda a piece of junk, but no, there's nothing that has the features of: being able to see agent diffs in an editor, seeing diffs inline in chat, be able to click them to jump to the code, and being able to click old chat messages to edit/fork them.
Those are basically my only requirements, and it feels like I've tried everything and they're all everything only has 1 of those features. Zed is the closest, it technically has those features, they're just buggy and have provider specific quirks.
So I'm stuck on Cursor until Anthropic invents IDE technology, or at least VS Code wrapper technology.
Jetbrains IDEs have AI support with all the things you've described, and in a more polished experience that requires significantly less maintenance and tuning. It does that while affording an actual IDE experience that works well for supported languages/projects out of the box, without the need to constantly tune plugins and experience jank misaligned UX that seems to be the norm for VSCode and derivatives.
No association with Jetbrains, and despite having a license, don't even use their AI support much myself (mostly using CC, with IDE integration for diff viewing). But if you haven't tried it recently, probably worth a revisit if you're open to Jetbrains products.
I hope their models improve. I used Junie when it first came out and it was okay but unreliable. I use Cursor with composer right now and I never have any issues. I sure do miss using PyCharm though.
Those are basically my only requirements, and it feels like I've tried everything and they're all everything only has 1 of those features. Zed is the closest, it technically has those features, they're just buggy and have provider specific quirks.
So I'm stuck on Cursor until Anthropic invents IDE technology, or at least VS Code wrapper technology.