refactor(pcre): hand back the match instead of copying it out

Preg::match4 and Preg::replace_callback gave callers a
PregMatchedGroups: an IndexMap rebuilt from the match with an owned
String per group, plus a second String for a named group's name key.
That is the copy PregMatches shed when it started wrapping
regex::Captures, reinstated one layer up -- and nearly every regex call
in the tree goes through Preg rather than the shim's preg_* directly, so
almost nothing saw the borrow.

PregMatchedGroups existed only to drop the null (unmatched) groups the
old PregMatches held as Option<String> values. PregMatches::get reports
a non-participating group as None on its own, so the two read alike and
the type collapses into it. Call sites still reach groups through
get(&CaptureKey::ByIndex(N)); what changes is that the value arrives as
a &str borrowed from the subject, which the signatures now carry as a
lifetime.

Three places needed the borrow reckoned with rather than a mechanical
rewrite: PhpFileCleaner::clean and Problem::get_messages read their
groups out before mutating what the match borrows, and
Git::get_authentication_failure names the lifetime of its url argument,
which the result borrows instead of self.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

3 files changed, 17 insertions, 14 deletions

diff --git a/crates/shirabe/src/downloader/git_downloader.rs b/crates/shirabe/src/downloader/git_downloader.rs
index d3f4441a..83f72300 100644
--- a/crates/shirabe/src/downloader/git_downloader.rs
+++ b/crates/shirabe/src/downloader/git_downloader.rs
@@ -101,8 +101,8 @@ impl GitDownloader {
         };
         let head_ref = head_match
             .get(&CaptureKey::ByIndex(1))
-            .cloned()
-            .unwrap_or_default();
+            .unwrap_or_default()
+            .to_string();
 
         let branches_match = Preg::is_match_all(
             format!("{{^{} refs/heads/(.+)$}}mi", preg_quote(&head_ref, None)),
@@ -513,16 +513,16 @@ impl GitDownloader {
             let protocols = self.inner.config.borrow_mut().get("github-protocols");
             let m1 = match_
                 .get(&CaptureKey::ByIndex(1))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             let m2 = match_
                 .get(&CaptureKey::ByIndex(2))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             let m3 = match_
                 .get(&CaptureKey::ByIndex(3))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             let mut push_url = format!("git@{}:{}/{}.git", m1, m2, m3);
             if !in_array_strict("ssh".to_string(), protocols.values()) {
                 push_url = format!("https://{}/{}/{}.git", m1, m2, m3);
@@ -1112,12 +1112,12 @@ impl VcsDownloader for GitDownloader {
         {
             let origin_url = origin_match
                 .get(&CaptureKey::ByName("url".to_string()))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             let composer_url = composer_match
                 .get(&CaptureKey::ByName("url".to_string()))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             if origin_url == composer_url
                 && Some(composer_url.as_str()) != target.get_source_url().as_deref()
             {
diff --git a/crates/shirabe/src/downloader/svn_downloader.rs b/crates/shirabe/src/downloader/svn_downloader.rs
index ce908206..d146337a 100644
--- a/crates/shirabe/src/downloader/svn_downloader.rs
+++ b/crates/shirabe/src/downloader/svn_downloader.rs
@@ -386,8 +386,8 @@ impl VcsDownloader for SvnDownloader {
             let base_url = if let Some(matches) = Preg::match3(url_pattern, &output) {
                 matches
                     .get(&CaptureKey::ByIndex(1))
-                    .cloned()
                     .unwrap_or_default()
+                    .to_string()
             } else {
                 return Err(RuntimeException::new(format!(
                     "Unable to determine svn url for path {}",
diff --git a/crates/shirabe/src/downloader/zip_downloader.rs b/crates/shirabe/src/downloader/zip_downloader.rs
index cefada15..8ecd131f 100644
--- a/crates/shirabe/src/downloader/zip_downloader.rs
+++ b/crates/shirabe/src/downloader/zip_downloader.rs
@@ -116,7 +116,10 @@ impl ZipDownloader {
                 && let Some(m) =
                     Preg::is_match3(php_regex!(r"{^\s*7-Zip(?:\s\[64\])?\s([0-9.]+)}"), &output)
             {
-                let m1 = m.get(&CaptureKey::ByIndex(1)).cloned().unwrap_or_default();
+                let m1 = m
+                    .get(&CaptureKey::ByIndex(1))
+                    .unwrap_or_default()
+                    .to_string();
                 if version_compare(&m1, "21.01", CmpOp::Lt) {
                     self.inner.io.borrow().write_error(&format!(
                         "    <warning>Unzipping using {} {} may result in incorrect file permissions. Install {} 21.01+ or unzip to ensure you get correct permissions.</warning>",