## Summary
This PR takes the functions used in `pip install`, moves them into a
common module, and then replaces all the `pip sync` logic with calls
into those functions. The net effect is that `pip install` and `pip
sync` share far more code and demonstrate much more consistent behavior.
Closes https://github.com/astral-sh/uv/issues/3555.
## Summary
This PR adds editables using a new source type (`editable+...`), and
then extracts the editables from the lockfile in `uv sync`.
Closes https://github.com/astral-sh/uv/issues/3695.
Needed to prevent circular dependencies in my toolchain work (#2931). I
think this is probably a reasonable change as we move towards persistent
configuration too?
Unfortunately `BuildIsolation` needs to be in `uv-types` to avoid
circular dependencies still. We might be able to resolve that in the
future.
Charlie Marsh
Zanie Blue