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, 5 deletions

diff --git a/crates/shirabe/src/util/remote_filesystem.rs b/crates/shirabe/src/util/remote_filesystem.rs
index 0bc004ce..e55e5200 100644
--- a/crates/shirabe/src/util/remote_filesystem.rs
+++ b/crates/shirabe/src/util/remote_filesystem.rs
@@ -13,7 +13,7 @@ use crate::util::Url;
 use crate::util::http::ProxyManager;
 use crate::util::http::Response;
 use indexmap::IndexMap;
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{
     PhpMixed, RuntimeException, STREAM_NOTIFY_FAILURE, STREAM_NOTIFY_FILE_SIZE_IS,
@@ -149,10 +149,7 @@ impl RemoteFilesystem {
         let mut value: Option<i64> = None;
         for header in headers {
             if let Some(m) = Preg::is_match3(php_regex!("{^HTTP/\\S+ (\\d+)}i"), header) {
-                value = m
-                    .get(&CaptureKey::ByIndex(1))
-                    .and_then(|s| s.parse().ok())
-                    .or(Some(0));
+                value = m.get(1).and_then(|s| s.parse().ok()).or(Some(0));
             }
         }