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/forgejo_url.rs b/crates/shirabe/src/util/forgejo_url.rs
index 7f9333e0..9ae1cbee 100644
--- a/crates/shirabe/src/util/forgejo_url.rs
+++ b/crates/shirabe/src/util/forgejo_url.rs
@@ -38,14 +38,9 @@ impl ForgejoUrl {
     pub fn try_from(repo_url: Option<&str>) -> Option<Self> {
         let repo_url = repo_url?;
         let matches = Preg::match3(Self::URL_REGEX, repo_url)?;
-        use shirabe_pcre::CaptureKey;
+
         let m: Vec<String> = (0..5)
-            .map(|i| {
-                matches
-                    .get(&CaptureKey::ByIndex(i))
-                    .unwrap_or_default()
-                    .to_string()
-            })
+            .map(|i| matches.get(i).unwrap_or_default().to_string())
             .collect();
 
         let origin_url = if !m[1].is_empty() {