## Summary
The strategy here is: if the user provides supported environments, we
use those as the initial forks when resolving. As a result, we never add
or explore branches that are disjoint with the supported environments.
(If the supported environments change, we ignore the lockfile entirely,
so we don't have to worry about any interactions between supported
environments and the preference forks.)
Closes https://github.com/astral-sh/uv/issues/6184.
This already rejects `pyproject.toml`... but because the schema
validation is relaxed (we allow unknown fields, and all fields are
optional), a `pyproject.toml` doesn't get properly rejected here.
This PR makes the schema stricter, but in a safe way (by adding the
other `tool.uv` fields, like `workspace`, as any).
Closes#5832.
Resolves#4467.
## Summary
This PR implements the following
1. Add `tool.uv.constraint-dependencies` to pyproject.toml
1. Support to refer `tool.uv.constraint-dependencies` in `uv lock`
1. Support to refer `tool.uv.constraint-dependencies` in `uv pip
compile/install`
These are analogues of the override features implemented in #3839 and
#4369.
## Test Plan
Add test.
Charlie Marsh
Di-Is