Add support for package-level conflicts in workspaces

crates/uv-configuration/src/preview.rs

@@ -14,7 +14,8 @@ bitflags::bitflags! {
         const JSON_OUTPUT = 1 << 2;
         const PYLOCK = 1 << 3;
         const ADD_BOUNDS = 1 << 4;
-        const EXTRA_BUILD_DEPENDENCIES = 1 << 5;
+        const PACKAGE_CONFLICTS = 1 << 5;
+        const EXTRA_BUILD_DEPENDENCIES = 1 << 6;
     }
 }
 
@@ -29,6 +30,7 @@ impl PreviewFeatures {
             Self::JSON_OUTPUT => "json-output",
             Self::PYLOCK => "pylock",
             Self::ADD_BOUNDS => "add-bounds",
+            Self::PACKAGE_CONFLICTS => "package-conflicts",
             Self::EXTRA_BUILD_DEPENDENCIES => "extra-build-dependencies",
             _ => panic!("`flag_as_str` can only be used for exactly one feature flag"),
         }
@@ -72,6 +74,7 @@ impl FromStr for PreviewFeatures {
                 "json-output" => Self::JSON_OUTPUT,
                 "pylock" => Self::PYLOCK,
                 "add-bounds" => Self::ADD_BOUNDS,
+                "package-conflicts" => Self::PACKAGE_CONFLICTS,
                 "extra-build-dependencies" => Self::EXTRA_BUILD_DEPENDENCIES,
                 _ => {
                     warn_user_once!("Unknown preview feature: `{part}`");
@@ -235,6 +238,10 @@ mod tests {
         assert_eq!(PreviewFeatures::JSON_OUTPUT.flag_as_str(), "json-output");
         assert_eq!(PreviewFeatures::PYLOCK.flag_as_str(), "pylock");
         assert_eq!(PreviewFeatures::ADD_BOUNDS.flag_as_str(), "add-bounds");
+        assert_eq!(
+            PreviewFeatures::PACKAGE_CONFLICTS.flag_as_str(),
+            "package-conflicts"
+        );
         assert_eq!(
             PreviewFeatures::EXTRA_BUILD_DEPENDENCIES.flag_as_str(),
             "extra-build-dependencies"