Help test the new stage-hunks-in-main-view feature

In case you missed it, I have been working on a major change to lazygit which gets rid of the staging and custom-patch-building panels, and allows staging hunks directly from the main view instead. See #5732 for more, which is a prototype of that.

I have started to reimplement the prototype for real, and am far enough that I think it's worth testing it already. There's no PR yet (it's actually going to be a stack of at least 8 PRs, maybe more), but I have an integration branch where everything is squashed and allows testing it. I have been using that branch in my daily work for quite a while now, so you can trust me that it's reasonably stable.

You can install this build using

```sh
go install github.com/jesseduffield/lazygit@sh-integration
```

If you are using any of the diff renderers delta, difftastic, or diff-so-fancy, you need special builds of these as well to make the whole thing fun. You can install them as follows:

- **delta**:
```
cargo install --git ssh://git@github.com/stefanhaller/delta.git --branch osc-1717-metadata
```
- **difftastic**:
```
cargo install --git ssh://git@github.com/stefanhaller/difftastic.git --branch osc-1717-metadata
```
- **diff-so-fancy**: download it from [here](https://raw.githubusercontent.com/stefanhaller/diff-so-fancy/refs/heads/osc-1717-metadata/diff-so-fancy) and put it somewhere in your PATH.

Make sure that `~/go/bin` and `~/.cargo/bin` are in your PATH.

I'm very interested in feedback; both about things that simply don't work right yet, and about things where the UX has changed for the worse in your opinion. Since we don't have a PR yet, I'm opening this issue as a place to give feedback.

A few features that may not be obvious to find:
- select a line or hunk in the main view, and press `e` to jump to your editor on that line
- even easier: hold option or shift (depending on your terminal) and click a line to edit it (this works even if it is behind a popup, e.g. the commit message editor)
- with the main view focused, press `f` to bring up a menu with all the files in the diff, to quickly jump to one (this menu can be filtered simply by typing, no need to press `/`)

Install the integration build with the provided go install command, ensuring the required binary paths are available; install a special diff renderer build if you use one. Exercise staging hunks, line editing, file navigation, and popup interactions in the main view, then report reproducible failures or UX regressions in this issue.

Written by the indexing model from the issue text.