Fix thread/list cwd filtering for Windows verbatim paths (#17414)

Addresses #17302

Problem: `thread/list` compared cwd filters with raw path equality, so
`resume --last` could miss Windows sessions when the saved cwd used a
verbatim path form and the current cwd did not.

Solution: Normalize cwd comparisons through the existing path comparison
utilities before falling back to direct equality, and add Windows
regression coverage for verbatim paths. I made this a general utility
function and replaced all of the duplicated instance of it across the
code base.

codex-rs/rollout/src/recorder.rs

@@ -1342,13 +1342,7 @@ async fn select_resume_path_from_db_page(
 }
 
 fn cwd_matches(session_cwd: &Path, cwd: &Path) -> bool {
-    if let (Ok(ca), Ok(cb)) = (
-        path_utils::normalize_for_path_comparison(session_cwd),
-        path_utils::normalize_for_path_comparison(cwd),
-    ) {
-        return ca == cb;
-    }
-    session_cwd == cwd
+    path_utils::paths_match_after_normalization(session_cwd, cwd)
 }
 
 #[cfg(test)]