## Summary
This PR enables the resolver to "accept" URLs, prereleases, and local
version specifiers for direct dependencies of path dependencies. As a
result, `uv pip install .` and `uv pip install -e .` now behave
identically, in that neither has a restriction on URL dependencies and
the like.
Closes https://github.com/astral-sh/uv/issues/2643.
Closes https://github.com/astral-sh/uv/issues/1853.
This is driving me a little crazy and is becoming a larger problem in
#2596 where I need to move more types (like `Upgrade` and `Reinstall`)
into this crate. Anything that's shared across our core resolver,
install, and build crates needs to be defined in this crate to avoid
cyclic dependencies. We've outgrown it being a single file with some
shared traits.
There are no behavioral changes here.
