refactor(preg): split PregMatches reads into get() and name()

PregMatches keyed both forms of a capture group through CaptureKey, so
every read built one: a usize wrapped in an enum, or worse, a String
allocated to name a group that regex::Captures can look up from a &str.
It now mirrors regex::Captures instead -- get() takes the group number,
name() the group name -- and the enum drops out of the type entirely.

That is 285 call sites across 59 files, and the named ones carry most of
the win: `matches.get(&CaptureKey::ByName("host".to_string()))` reads as
`matches.name("host")`. ProcessExecutor loses a `user_key` binding that
existed only to build the key once.

CaptureKey stays as the key type of PregMatchesAll and
PregMatchesAllWithOffsets, where numbered and named entries share one
IndexMap and a key type is the point. Five files still name it.

Also retargets the two preg_match_all comments that described the
occurrence count through `matches[&CaptureKey::ByIndex(0)].len()`, an
Index impl these types no longer carry.

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

3 files changed, 10 insertions, 34 deletions

diff --git a/crates/shirabe/src/downloader/git_downloader.rs b/crates/shirabe/src/downloader/git_downloader.rs
index 83f72300..b816aa18 100644
--- a/crates/shirabe/src/downloader/git_downloader.rs
+++ b/crates/shirabe/src/downloader/git_downloader.rs
@@ -99,10 +99,7 @@ impl GitDownloader {
             // could not match the HEAD for some reason
             return Ok(None);
         };
-        let head_ref = head_match
-            .get(&CaptureKey::ByIndex(1))
-            .unwrap_or_default()
-            .to_string();
+        let head_ref = head_match.get(1).unwrap_or_default().to_string();
 
         let branches_match = Preg::is_match_all(
             format!("{{^{} refs/heads/(.+)$}}mi", preg_quote(&head_ref, None)),
@@ -511,18 +508,9 @@ impl GitDownloader {
             url,
         ) {
             let protocols = self.inner.config.borrow_mut().get("github-protocols");
-            let m1 = match_
-                .get(&CaptureKey::ByIndex(1))
-                .unwrap_or_default()
-                .to_string();
-            let m2 = match_
-                .get(&CaptureKey::ByIndex(2))
-                .unwrap_or_default()
-                .to_string();
-            let m3 = match_
-                .get(&CaptureKey::ByIndex(3))
-                .unwrap_or_default()
-                .to_string();
+            let m1 = match_.get(1).unwrap_or_default().to_string();
+            let m2 = match_.get(2).unwrap_or_default().to_string();
+            let m3 = match_.get(3).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);
@@ -1110,14 +1098,8 @@ impl VcsDownloader for GitDownloader {
             && let Some(composer_match) =
                 Preg::is_match3(php_regex!(r"{^composer\s+(?P<url>\S+)}m"), &output)
         {
-            let origin_url = origin_match
-                .get(&CaptureKey::ByName("url".to_string()))
-                .unwrap_or_default()
-                .to_string();
-            let composer_url = composer_match
-                .get(&CaptureKey::ByName("url".to_string()))
-                .unwrap_or_default()
-                .to_string();
+            let origin_url = origin_match.name("url").unwrap_or_default().to_string();
+            let composer_url = composer_match.name("url").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 d146337a..4931e539 100644
--- a/crates/shirabe/src/downloader/svn_downloader.rs
+++ b/crates/shirabe/src/downloader/svn_downloader.rs
@@ -15,7 +15,7 @@ use crate::util::Filesystem;
 use crate::util::ProcessExecutor;
 use crate::util::Svn as SvnUtil;
 use indexmap::IndexMap;
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::{
     CmpOp, PhpMixed, RuntimeException, impl_php_class, is_dir, php_regex, preg_split,
     version_compare,
@@ -384,10 +384,7 @@ impl VcsDownloader for SvnDownloader {
 
             let url_pattern = "#<url>(.*)</url>#";
             let base_url = if let Some(matches) = Preg::match3(url_pattern, &output) {
-                matches
-                    .get(&CaptureKey::ByIndex(1))
-                    .unwrap_or_default()
-                    .to_string()
+                matches.get(1).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 8ecd131f..b4802066 100644
--- a/crates/shirabe/src/downloader/zip_downloader.rs
+++ b/crates/shirabe/src/downloader/zip_downloader.rs
@@ -8,7 +8,7 @@ use crate::package::PackageInterfaceHandle;
 use crate::util::IniHelper;
 use crate::util::Platform;
 use indexmap::IndexMap;
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{
     CmpOp, ErrorException, PhpMixed, RuntimeException, UnexpectedValueException, ZipArchive,
@@ -116,10 +116,7 @@ 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))
-                    .unwrap_or_default()
-                    .to_string();
+                let m1 = m.get(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>",