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, 7 deletions

diff --git a/crates/shirabe/src/util/svn.rs b/crates/shirabe/src/util/svn.rs
index 72ca2321..5ff6a025 100644
--- a/crates/shirabe/src/util/svn.rs
+++ b/crates/shirabe/src/util/svn.rs
@@ -6,7 +6,7 @@ use crate::io::IOInterfaceImmutable;
 use crate::io::io_interface;
 use crate::util::Platform;
 use crate::util::ProcessExecutor;
-use shirabe_pcre::{CaptureKey, Preg};
+use shirabe_pcre::Preg;
 use shirabe_php_shim::{
     LogicException, PhpMixed, RuntimeException, implode, parse_url, php_regex, stripos, strpos,
     trim,
@@ -407,12 +407,7 @@ impl Svn {
                 None,
             ) && let Some(matches) = Preg::is_match3(php_regex!(r"{(\d+(?:\.\d+)+)}"), &output)
             {
-                *cached = Some(
-                    matches
-                        .get(&CaptureKey::ByIndex(1))
-                        .unwrap_or_default()
-                        .to_string(),
-                );
+                *cached = Some(matches.get(1).unwrap_or_default().to_string());
             }
         }