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, 2 insertions, 2 deletions

diff --git a/crates/shirabe/src/package/locker.rs b/crates/shirabe/src/package/locker.rs
index f27f44a2..7d45e573 100644
--- a/crates/shirabe/src/package/locker.rs
+++ b/crates/shirabe/src/package/locker.rs
@@ -24,7 +24,7 @@ use crate::repository::RootPackageRepository;
 use crate::util::Git as GitUtil;
 use crate::util::ProcessExecutor;
 use indexmap::IndexMap;
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{
     DATE_RFC3339, LogicException, PhpMixed, RuntimeException, array_intersect, array_keys,
@@ -848,7 +848,7 @@ impl Locker {
                         output.as_string().unwrap_or(""),
                     ) {
                         let ts = m
-                            .get(&CaptureKey::ByIndex(1))
+                            .get(1)
                             .unwrap_or_default()
                             .to_string()
                             .parse::<i64>()