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, 3 insertions, 3 deletions

diff --git a/crates/shirabe/tests/all_functional_test.rs b/crates/shirabe/tests/all_functional_test.rs
index ad075ad6..d947a054 100644
--- a/crates/shirabe/tests/all_functional_test.rs
+++ b/crates/shirabe/tests/all_functional_test.rs
@@ -9,7 +9,7 @@ use indexmap::IndexMap;
 use serial_test::serial;
 use shirabe::util::filesystem::Filesystem;
 use shirabe_pcre::preg::Preg;
-use shirabe_php_shim::{CaptureKey, PhpMixed, intval, php_regex, preg_split_delim_capture};
+use shirabe_php_shim::{PhpMixed, intval, php_regex, preg_split_delim_capture};
 use std::path::{Path, PathBuf};
 
 /// ref: AllFunctionalTest's `$oldcwd` / `$testDir` instance state plus its `setUp`/`tearDown`.
@@ -144,11 +144,11 @@ fn expect_matches(expected: &str, output: &str) {
             let Some(m) = Preg::is_match3(php_regex!("{%(.+?)%}"), &expected[i..]) else {
                 panic!("Failed to match %...% in {}", &expected[i..]);
             };
-            let regex = m.get(&CaptureKey::ByIndex(1)).map(str::to_string).unwrap();
+            let regex = m.get(1).map(str::to_string).unwrap();
 
             let pattern = format!("{{{}}}", regex);
             if let Some(m) = Preg::is_match3(&pattern, &output[j..]) {
-                let full = m.get(&CaptureKey::ByIndex(0)).map(str::to_string).unwrap();
+                let full = m.get(0).map(str::to_string).unwrap();
                 i += regex.len() + 2;
                 j += full.len();
                 continue;