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, 3 deletions

diff --git a/crates/shirabe/src/command/init_command.rs b/crates/shirabe/src/command/init_command.rs
index f9a504be..81e1e381 100644
--- a/crates/shirabe/src/command/init_command.rs
+++ b/crates/shirabe/src/command/init_command.rs
@@ -94,7 +94,9 @@ impl InitCommand {
             php_regex!(r#"/^(?P<name>[- .,\p{L}\p{N}\p{Mn}\'’\"()]+)(?:\s+<(?P<email>.+?)>)?$/u"#),
             author,
         ) {
-            let email = m.get(&CaptureKey::ByName("email".to_string())).cloned();
+            let email = m
+                .get(&CaptureKey::ByName("email".to_string()))
+                .map(str::to_string);
             if let Some(ref email) = email
                 && !self.is_valid_email(email)
             {
@@ -107,8 +109,7 @@ impl InitCommand {
             result.insert(
                 "name".to_string(),
                 Some(trim(
-                    &m.get(&CaptureKey::ByName("name".to_string()))
-                        .cloned()
+                    m.get(&CaptureKey::ByName("name".to_string()))
                         .unwrap_or_default(),
                     None,
                 )),