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>

1 files changed, 4 insertions, 4 deletions

diff --git a/crates/shirabe/src/command/archive_command.rs b/crates/shirabe/src/command/archive_command.rs
index 09066c9f..c2166b45 100644
--- a/crates/shirabe/src/command/archive_command.rs
+++ b/crates/shirabe/src/command/archive_command.rs
@@ -234,12 +234,12 @@ impl ArchiveCommand {
         {
             let m1 = matches
                 .get(&CaptureKey::ByIndex(1))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             let m0 = matches
                 .get(&CaptureKey::ByIndex(0))
-                .cloned()
-                .unwrap_or_default();
+                .unwrap_or_default()
+                .to_string();
             min_stability = VersionParser::normalize_stability(&m1)?;
             let full_match_len = m0.len();
             version = Some(version_str[..version_str.len() - full_match_len].to_string());