Extract build commands into uv-build-commands (#22260)
## Summary
We move `uv build` into `uv-build-commands`, giving build orchestration
its own compilation boundary alongside the other command families. The
existing `uv-build-frontend` remains the shared interface to build
backends.
The `uv` crate supplies the diagnostic renderer used when reporting
failed builds, so error hints still use the central routing. The new
crate has no dependency on sibling command crates.
We fold the implementation into the command entrypoint and return
`ExitStatus` directly. This removes a forwarding call and the private
`BuildResult` enum used only to translate the result into an exit
status.
The instrumented x86_64 Linux release build exceeds 16 GB of memory with
the split crates, so we give its PGO job a 64 GB runner.
## Crate structure
Selected dependencies after the complete split:
```text
uv (process initialization, dispatch, remaining commands)
|
+-- uv-cli (argument parsing and settings resolution)
+-- uv-python-commands -------> uv-python-context
+-- uv-pip-commands ----------> uv-{resolve,install}-operations
+-- uv-project-commands ------> uv-{lock,environment,audit}-operations
| (including init)
+-- uv-workspace-commands ----> uv-{lock,environment}-operations
+-- uv-tool-commands ---------> uv-{lock,environment,audit}-operations
+-- uv-build-commands --------> uv-build-frontend, uv-dispatch, uv-python-context
`-- uv-publish-commands ------> uv-publish
uv-lock-operations ----------> uv-resolve-operations
uv-environment-operations ---> uv-{resolve,install}-operations
`--> uv-python-context
```
## Benchmarks
We split command families and shared workflows so local edits can reuse
more compiled code and rebuild faster.
We replayed these historical production changes on the stack’s base
([`822539467`](https://github.com/astral-sh/uv/commit/822539467aa0744075b4ffde516db85ed0a547c5))
and final layout
([`129123230`](https://github.com/astral-sh/uv/commit/129123230ccf1e2e2318bbd235c370edc0958d5e)).
Times are medians of three paired development-binary rebuilds, including
linking, on Linux with stock Rust 1.99.0 and 16 Cargo jobs. Each replay
starts from a warmed before-state. The comparison covers the full stack,
including its prerequisite refactors.
| Historical change | Before | After | Reduction |
| --- | ---: | ---: | ---: |
| [Project add: empty metadata
cache](https://github.com/astral-sh/uv/commit/6cf775b65384d2fd549c6e858972de433c19bfab)
| 12.25s | 8.39s | 31.5% |
| [Project sync: workspace
warning](https://github.com/astral-sh/uv/commit/c4e9150bc11eb29ae8f366430332b9592b9f9044)
| 12.07s | 6.92s | 42.7% |
| [CLI/settings: audit group
selection](https://github.com/astral-sh/uv/commit/410a67e5a9297594538d4f616c532191f8c052c2)
| 14.44s | 8.95s | 38.0% |
| [Install operations: dry-run
distributions](https://github.com/astral-sh/uv/commit/ab8220dd143153fe24f1ba06c703b8a4d209e251)
| 14.18s | 9.40s | 33.7% |
| [Lock metadata API and workspace
command](https://github.com/astral-sh/uv/commit/ba5833f0988962079e75894490f576c7f8cccf49)
| 16.74s | 11.67s | 30.3% |
| [Lock internals: conflicting
groups](https://github.com/astral-sh/uv/commit/fc012a663191c4bf3c8af5915ac51524d10ba13d)
| 22.21s | 14.41s | 35.1% |
| [Python installation type and
command](https://github.com/astral-sh/uv/commit/7a3bc07950e733a967e745337e9189b6d3def9c2)
| 43.11s | 29.37s | 31.9% |
Lower wall times can require more total CPU; gains depend on available
parallelism.
