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>

1 files changed, 5 insertions, 5 deletions

diff --git a/crates/shirabe/src/util/composer_mirror.rs b/crates/shirabe/src/util/composer_mirror.rs
index 5d9e8c31..f7bc179f 100644
--- a/crates/shirabe/src/util/composer_mirror.rs
+++ b/crates/shirabe/src/util/composer_mirror.rs
@@ -1,6 +1,6 @@
 //! ref: composer/src/Composer/Util/ComposerMirror.php
 
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::{hash, php_regex};
 
 pub struct ComposerMirror;
@@ -61,8 +61,8 @@ impl ComposerMirror {
         ) {
             format!(
                 "gh-{}/{}",
-                gh_matches.get(&CaptureKey::ByIndex(1)).unwrap_or_default(),
-                gh_matches.get(&CaptureKey::ByIndex(2)).unwrap_or_default(),
+                gh_matches.get(1).unwrap_or_default(),
+                gh_matches.get(2).unwrap_or_default(),
             )
         } else if let Some(bb_matches) = Preg::match3(
             php_regex!(r"#^https://bitbucket\.org/([^/]+)/(.+?)(?:\.git)?/?$#"),
@@ -70,8 +70,8 @@ impl ComposerMirror {
         ) {
             format!(
                 "bb-{}/{}",
-                bb_matches.get(&CaptureKey::ByIndex(1)).unwrap_or_default(),
-                bb_matches.get(&CaptureKey::ByIndex(2)).unwrap_or_default(),
+                bb_matches.get(1).unwrap_or_default(),
+                bb_matches.get(2).unwrap_or_default(),
             )
         } else {
             Preg::replace(php_regex!(r"{[^a-z0-9_.-]}i"), "-", url.trim_matches('/'))