This turns two Merge-s into an object that represents a way to present their difference to the user, in the form of `Vec<DiffExplanationAtom>`.

`DiffExplanationAtom` is the key structure for the data model of differences between diffs.

The algorithm is inefficient and far from perfect, for now my focus is on the data model.

For textual conflicts, the distance function will be the size of the diff between two chunks of text.

This represents a diff of two merges, up to reordering and cancelling
out of terms. It can also be thought of as a stack of `n` diffs.

This type is not very suitable for presenting to the user (since it
loses information they might want to see), but is very natural from the
perspective of conflict theory.

This reorders the result slightly and makes it easier to generalize this to work on diffs of merges (where there is the same number of adds and removes).

These will be used for diffs of Merge-s.

This also refactors one of the less important tests. I did it mostly automatically with `ast-grep` (which I don't necessarily recommend), but we could also just delete this test I think.

We have many callers of materialize_merge_result() who just want in-memory
buffer.

Because the output of diff.hunks() is a list of [&BStr]s, a Merge object
reconstructed from a diff hunk will be Merge<&BStr>. I'm not pretty sure if
we'll implement conflict diffs in that way, but this change should be harmless
anyway.

I'm going to make materialize_merge_result() accept reference type. This patch
extracts large non-generic part to a separate function.

I believe this was an oversight. "jj duplicate" should duplicate commits (=
patches), not trees.

This patch adds a separate test file because test_rewrite.rs is pretty big, and
we'll probably want to migrate CLI tests to jj-lib.

Bumps the github-dependencies group with 2 updates: [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv) and [github/codeql-action](https://github.com/github/codeql-action).


Updates `astral-sh/setup-uv` from 3.2.2 to 3.2.3
- [Release notes](https://github.com/astral-sh/setup-uv/releases)
- [Commits](https://github.com/astral-sh/setup-uv/compare/2e657c127d5b1635d5a8e3fa40e0ac50a5bf6992...e779db74266a80753577425b0f4ee823649f251d)

Updates `github/codeql-action` from 3.27.4 to 3.27.5
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/ea9e4e37992a54ee68a9622e985e60c8e8f12d9f...f09c1c0a94de965c15400f5634aa42fac8fb8f88)

---
updated-dependencies:
- dependency-name: astral-sh/setup-uv
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: github-dependencies
- dependency-name: github/codeql-action
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: github-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Our docs are built with MkDocs, which requires Python and several deps.

Previously those deps were managed with Poetry, which is also written in Python.
This commit replaces Poetry with `uv`, a Rust-based Python
project/package manager, and thus removes several steps from the docs
build process.

Before:

<install Python>
<install pipx>
pipx install poetry
poetry install
poetry run -- mkdocs serve

After:

<install uv>
uv run mkdocs serve

The working-copy revision is usually the latest commit, but it's not always
true. This patch ensures that the wc branch is emitted first so the graph node
order is less dependent on rewrites.

This isn't always fast because it increases the chance of cache miss, but in
practice, it makes "jj file annotate" faster. It's still slower than
"git blame", though.

Maybe we should also change the hash function.

```
group new old
----- --- ---
bench_diff_git_git_read_tree_c 1.00 45.2±0.38µs 1.29 58.4±0.32µs
bench_diff_lines/modified/10k 1.00 32.7±0.24ms 1.05 34.4±0.17ms
bench_diff_lines/modified/1k 1.00 2.9±0.00ms 1.06 3.1±0.01ms
bench_diff_lines/reversed/10k 1.00 22.7±0.18ms 1.02 23.2±0.29ms
bench_diff_lines/reversed/1k 1.00 439.0±9.46µs 1.19 523.9±6.05µs
bench_diff_lines/unchanged/10k 1.00 2.9±0.06ms 1.20 3.5±0.02ms
bench_diff_lines/unchanged/1k 1.00 240.8±1.03µs 1.30 312.1±1.05µs
```

```
% hyperfine --sort command --warmup 3 --runs 10 -L bin jj-0,jj-1 \
'target/release-with-debug/{bin} --ignore-working-copy file annotate lib/src/revset.rs'
Benchmark 1: target/release-with-debug/jj-0 ..
Time (mean ± σ): 1.604 s ± 0.259 s [User: 1.543 s, System: 0.057 s]
Range (min … max): 1.348 s … 1.917 s 10 runs

Benchmark 2: target/release-with-debug/jj-1 ..
Time (mean ± σ): 1.183 s ± 0.026 s [User: 1.118 s, System: 0.062 s]
Range (min … max): 1.155 s … 1.237 s 10 runs
```

I'm going to add a Vec of precomputed hashes, and the Vec will be owned by
DiffSource.

Since patience diff is recursive, it makes some sense to reuse precomputed
hash values. This patch migrates Histogram to remembering hashed values. The
precomputed values will be cached globally by DiffSource.

Technically, Histogram doesn't have to keep a separate copy of hash values, but
this appears to give better perf than slicing text and hash value from two Vecs.

This makes it more consistent with `bookmarks()`.

Co-authored-by: Austin Seipp <aseipp@pobox.com>

Bumps the cargo-dependencies group with 1 update: [rustix](https://github.com/bytecodealliance/rustix).


Updates `rustix` from 0.38.40 to 0.38.41
- [Release notes](https://github.com/bytecodealliance/rustix/releases)
- [Changelog](https://github.com/bytecodealliance/rustix/blob/main/CHANGELOG.md)
- [Commits](https://github.com/bytecodealliance/rustix/compare/v0.38.40...v0.38.41)

---
updated-dependencies:
- dependency-name: rustix
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: cargo-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Add comparison for git blame and jj file annotate.

If you have multiple remotes to push to, you might want to keep some changes
(such as security patches) in your private fork. Git CLI has one upstream remote
per branch, but jj supports multiple tracking remotes, and therefore "jj git
push" can start tracking new remotes automatically.

This patch makes new bookmarks not eligible for push by default. I considered
adding a warning, but it's not always possible to interrupt the push shortly
after a warning is emitted.

--all implies --allow-new because otherwise it's equivalent to --tracked. It's
also easier to write a conflict rule with --all/--deleted/--tracked than with
two of them.

-c/--change doesn't require --allow-new because it is the flag to create new
tracking bookmark.

#1278

I hope we'll have support for copies and renames in not too long. It's
good to have as many versions before that as possible without support
for `jj move`, in case we want to later use that to record a moved
file (maybe as an alias for `jj file move`).

Bumps the cargo-dependencies group with 2 updates: [libc](https://github.com/rust-lang/libc) and [serde_json](https://github.com/serde-rs/json).


Updates `libc` from 0.2.162 to 0.2.164
- [Release notes](https://github.com/rust-lang/libc/releases)
- [Changelog](https://github.com/rust-lang/libc/blob/main/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/libc/compare/0.2.162...0.2.164)

Updates `serde_json` from 1.0.132 to 1.0.133
- [Release notes](https://github.com/serde-rs/json/releases)
- [Commits](https://github.com/serde-rs/json/compare/v1.0.132...v1.0.133)

---
updated-dependencies:
- dependency-name: libc
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: cargo-dependencies
- dependency-name: serde_json
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: cargo-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

There are two known limitations right now:

- Only statically known keys are suggested.

- Keys that the user did not set are still suggested for `jj config get`.
Running that suggestion may result in an error. The error message will be
appropriate though and there is some value in letting the user know that
this config value theoretically exists. Some users may try to explore what
configurations are available via the completions.

This is a workaround for command name completion. On zsh, the complete position
is specified by $_CLAP_COMPLETE_INDEX, and an empty argument isn't padded. So,
for "jj <TAB>", { args = ["jj"], index = 1 } is provided, and our expand_args()
helpfully fills in the default command "log". Since args[index] is now "log",
no other commands are listed.

It can be a footgun, and is inconsistent because other mutation commands can't
overwrite a table.

#4889

Signed-off-by: Tim Janik <timj@gnu.org>

Signed-off-by: Tim Janik <timj@gnu.org>

Perhaps it would be nice to point to the revset docs from every
argument that takes a revset, or perhaps that would be too
verbose. `jj log` is perhaps where most people first run into revset
syntax, so I hope pointing to the docs from there is a good start.

It's not obvious what the symbols mean. We've had a few questions
about it on Discord recently.

This also fixes the Xethub link, by pointing it to the web archive, which no longer is available.

People will often look for contributing instructions from
https://github.com/martinvonz/jj, this makes it easier
to find.

It will also lead more people to read the contributing
docs on the website as opposed to GitHub. This is becoming
desireable, see the discussion at
https://github.com/martinvonz/jj/pull/4822#discussion_r1844611306

It feels extraneous. People can just look at whether the GitHub UI shows a checkmark
next to the commit.

Bumps the github-dependencies group with 1 update: [DeterminateSystems/nix-installer-action](https://github.com/determinatesystems/nix-installer-action).


Updates `DeterminateSystems/nix-installer-action` from 15 to 16
- [Release notes](https://github.com/determinatesystems/nix-installer-action/releases)
- [Commits](https://github.com/determinatesystems/nix-installer-action/compare/b92f66560d6f97d6576405a7bae901ab57e72b6a...e50d5f73bfe71c2dd0aa4218de8f4afa59f8f81d)

---
updated-dependencies:
- dependency-name: DeterminateSystems/nix-installer-action
dependency-type: direct:production
update-type: version-update:semver-major
dependency-group: github-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

This can be used to find the fork point (best common ancestors) of a
revset with an arbitrary number of commits, which cannot be expressed
currently in the revset language.

This forces us to think about which repo should be used. It doesn't matter in
find_bookmarks_to_push() because moved "push-{change_id}" bookmarks are
prioritized. It doesn't matter in print_commits_ready_to_push() either, which
uses the repo only for ancestry lookup, but I think tx.repo() is better here.

This will be shared between `move_commits` and the new
`duplicate_commits` function to be added.

Closes #4846.

Bumps the github-dependencies group with 1 update: [github/codeql-action](https://github.com/github/codeql-action).


Updates `github/codeql-action` from 3.27.3 to 3.27.4
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/396bb3e45325a47dd9ef434068033c6d5bb0d11a...ea9e4e37992a54ee68a9622e985e60c8e8f12d9f)

---
updated-dependencies:
- dependency-name: github/codeql-action
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: github-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Bumps the cargo-dependencies group with 2 updates in the / directory: [bstr](https://github.com/BurntSushi/bstr) and [clap_complete](https://github.com/clap-rs/clap).


Updates `bstr` from 1.10.0 to 1.11.0
- [Commits](https://github.com/BurntSushi/bstr/compare/1.10.0...1.11.0)

Updates `clap_complete` from 4.5.37 to 4.5.38
- [Release notes](https://github.com/clap-rs/clap/releases)
- [Changelog](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md)
- [Commits](https://github.com/clap-rs/clap/compare/clap_complete-v4.5.37...clap_complete-v4.5.38)

---
updated-dependencies:
- dependency-name: bstr
dependency-type: direct:production
update-type: version-update:semver-minor
dependency-group: cargo-dependencies
- dependency-name: clap_complete
dependency-type: direct:production
update-type: version-update:semver-patch
dependency-group: cargo-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

This makes completions suggest aliases from the user or repository
configuration. It's more useful for long aliases that aren't used very often,
but serve the purpose of "executable documentation" of complex and useful jj
commands.

An earlier patch "resolved" aliases, meaning that any arguments following an
alias would be completed as if the normal command had been used. So it only
made sure that using aliases doesn't degrade the rest of the completions.
Commit ID: 325402dc9463ccaa70822069b3e94716d9cc7417

It was redundant once mainProgram was set for the package