fix: handle git dependencies without traditional filenames

- Add support for git dependencies that lack sdist filenames
- Generate synthetic filenames for git URLs (e.g., package-version.tar.gz)
- Include git dependencies with URLs like git+https://github.com/...
- Fixes missing candidates for average-minimum-distance and pormake

This ensures git-based dependencies are properly included in PEX lock
files with appropriate filenames for PEX resolution.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

crates/uv-resolver/src/lock/export/pex_lock.rs

@@ -197,7 +197,15 @@ impl PexLock {
                 let Some(sdist_url) = sdist.url().map(|u| u.to_string()) else {
                     continue;
                 };
-                let Some(sdist_filename) = sdist.filename().map(|f| f.to_string()) else {
+                
+                // Handle git dependencies that may not have traditional filenames
+                let sdist_filename = if let Some(filename) = sdist.filename() {
+                    filename.to_string()
+                } else if sdist_url.starts_with("git+") {
+                    // Generate a filename for git dependencies
+                    format!("{}-{}.tar.gz", package.id.name, 
+                           package.id.version.as_ref().map(|v| v.to_string()).unwrap_or_else(|| "0.0.0".to_string()))
+                } else {
                     continue;
                 };
 
@@ -229,8 +237,8 @@ impl PexLock {
                         {
                             // Only exclude dependencies that are TRULY Windows-only:
                             // - Have ONLY Windows wheels AND no source distribution
-                            let only_windows_wheels = !dep_package.wheels.is_empty() &&
+                            let only_windows_wheels = !dep_package.wheels.is_empty()
-                                dep_package.wheels.iter().all(|wheel| {
+                                && dep_package.wheels.iter().all(|wheel| {
                                     wheel.filename.platform_tags().iter().any(|tag| {
                                         matches!(
                                             tag,
@@ -242,7 +250,7 @@ impl PexLock {
                                     })
                                 });
                             let has_sdist = dep_package.sdist.is_some();
-                            
+
                             // Include unless it's Windows-only (only Windows wheels and no sdist)
                             let has_compatible_artifacts = !only_windows_wheels || has_sdist;