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, 4 insertions, 7 deletions

diff --git a/crates/shirabe/src/config.rs b/crates/shirabe/src/config.rs
index dd86149c..92b13fb8 100644
--- a/crates/shirabe/src/config.rs
+++ b/crates/shirabe/src/config.rs
@@ -8,7 +8,7 @@ pub use json_config_source::*;
 
 use crate::io::io_interface;
 use indexmap::IndexMap;
-use shirabe_pcre::{CaptureKey, Preg, PregMatches};
+use shirabe_pcre::{Preg, PregMatches};
 use shirabe_php_shim::{
     E_USER_DEPRECATED, PhpMixed, RuntimeException, array_key_exists, array_merge,
     array_search_mixed, array_unique, empty, filter_var_url, implode, in_array_loose,
@@ -658,12 +658,12 @@ impl Config {
                     .into());
                 };
                 let mut size = matches
-                    .get(&CaptureKey::ByIndex(1))
+                    .get(1)
                     .unwrap_or_default()
                     .to_string()
                     .parse::<f64>()
                     .unwrap_or(0.0);
-                let unit = matches.get(&CaptureKey::ByIndex(2)).map(str::to_string);
+                let unit = matches.get(2).map(str::to_string);
                 if let Some(unit) = unit {
                     match strtolower(&unit).as_str() {
                         "g" => {
@@ -960,10 +960,7 @@ impl Config {
         let result = Preg::replace_callback(
             php_regex!(r"#\{\$(.+)\}#"),
             |m: &PregMatches| -> String {
-                let key_match = m
-                    .get(&CaptureKey::ByIndex(1))
-                    .unwrap_or_default()
-                    .to_string();
+                let key_match = m.get(1).unwrap_or_default().to_string();
                 match self.get_with_flags(&key_match, flags) {
                     Ok(v) => php_to_string(&v),
                     Err(e) => {