Use separate types to represent raw vs. resolver markers (#6646)

## Summary

This is similar to https://github.com/astral-sh/uv/pull/6171 but more
expansive... _Anywhere_ that we test requirements for platform
compatibility, we _need_ to respect the resolver-friendly markers. In
fixing the motivating issue (#6621), I also realized that we had a bunch
of bugs here around `pip install` with `--python-platform` and
`--python-version`, because we always performed our `satisfy` and `Plan`
operations on the interpreter's markers, not the adjusted markers!

Closes https://github.com/astral-sh/uv/issues/6621.

crates/pypi-types/src/lib.rs

@@ -1,6 +1,7 @@
 pub use base_url::*;
 pub use direct_url::*;
 pub use lenient_requirement::*;
+pub use marker_environment::*;
 pub use metadata::*;
 pub use parsed_url::*;
 pub use requirement::*;
@@ -10,6 +11,7 @@ pub use simple_json::*;
 mod base_url;
 mod direct_url;
 mod lenient_requirement;
+mod marker_environment;
 mod metadata;
 mod parsed_url;
 mod requirement;

crates/pypi-types/src/marker_environment.rs

@@ -0,0 +1,53 @@
+use tracing::debug;
+
+use pep508_rs::MarkerEnvironment;
+
+/// A wrapper type around [`MarkerEnvironment`] that ensures the Python version markers are
+/// release-only, to match the resolver's semantics.
+#[derive(Debug, Clone)]
+pub struct ResolverMarkerEnvironment(MarkerEnvironment);
+
+impl ResolverMarkerEnvironment {
+    /// Returns the underlying [`MarkerEnvironment`].
+    pub fn markers(&self) -> &MarkerEnvironment {
+        &self.0
+    }
+}
+
+impl From<MarkerEnvironment> for ResolverMarkerEnvironment {
+    fn from(value: MarkerEnvironment) -> Self {
+        // Strip `python_version`.
+        let python_version = value.python_version().only_release();
+        let value = if python_version == **value.python_version() {
+            value
+        } else {
+            debug!(
+                "Stripping pre-release from `python_version`: {}",
+                value.python_version()
+            );
+            value.with_python_version(python_version)
+        };
+
+        // Strip `python_full_version`.
+        let python_full_version = value.python_full_version().only_release();
+        let value = if python_full_version == **value.python_full_version() {
+            value
+        } else {
+            debug!(
+                "Stripping pre-release from `python_full_version`: {}",
+                value.python_full_version()
+            );
+            value.with_python_full_version(python_full_version)
+        };
+
+        Self(value)
+    }
+}
+
+impl std::ops::Deref for ResolverMarkerEnvironment {
+    type Target = MarkerEnvironment;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}