Use raw command output for jj file reads, add encoding-aware decode/encode
handling, preserve buffer encoding settings across revision buffers, and add
tests for BOMs, endianness, and roundtrip behavior.
This new command is natively implemented by both the `codediff` and `diffview` backends allowing to easily navigate the changes between two revsets while diffing the.
It also gives a new `:J diff_hisotyr` command that optionally takes a range of revsets formatted `<rev1>..<rev2>` otherwise it prompts the user for the range.
- Refactor diff into modular architecture (native, diffview, codediff)
- Add the possibility for users to define their own diff backend
- Support external diff tools like diffview.nvim codediff.nvim
- Enable visual mode selection to diff two changes in log buffer
- Add summary tooltip integration with terminal
- Update documentation with new diff workflows
