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, 5 deletions

diff --git a/crates/shirabe/src/package/package.rs b/crates/shirabe/src/package/package.rs
index c987f2fe..2e2d5feb 100644
--- a/crates/shirabe/src/package/package.rs
+++ b/crates/shirabe/src/package/package.rs
@@ -434,11 +434,7 @@ impl Package {
             self.set_dist_url(Some(Preg::replace_callback(
                 php_regex!("{(/|sha=)[a-f0-9]{40}(/|$)}i"),
                 |m: &shirabe_pcre::PregMatches| -> String {
-                    let get = |i: usize| -> String {
-                        m.get(&shirabe_pcre::CaptureKey::ByIndex(i))
-                            .unwrap_or_default()
-                            .to_string()
-                    };
+                    let get = |i: usize| -> String { m.get(i).unwrap_or_default().to_string() };
                     format!("{}{}{}", get(1), reference, get(2))
                 },
                 &self.get_dist_url().unwrap_or_default(),