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, 1 insertions, 3 deletions

diff --git a/crates/shirabe/src/console/application.rs b/crates/shirabe/src/console/application.rs
index ca645635..25379a27 100644
--- a/crates/shirabe/src/console/application.rs
+++ b/crates/shirabe/src/console/application.rs
@@ -1792,9 +1792,7 @@ impl Application {
         let mut offset = 0i64;
         while let Some(m) = preg_match2(php_regex!(r"/.{1,10000}/u"), &utf8_string, offset as usize)
         {
-            let m0 = m
-                .get(&shirabe_php_shim::CaptureKey::ByIndex(0))
-                .unwrap_or("");
+            let m0 = m.get(0).unwrap_or("");
             offset += shirabe_php_shim::strlen(m0);
 
             let chunk = m0;