refactor(pcre): inline Preg into its call sites and drop the crate

Preg had shed everything it owned: after the last few rounds its methods
were one-line forwards to the shim's preg_*(), differing only in a
default argument or a wrapper the caller unwrapped anyway. The 460 call
sites now name the shim function, and shirabe-pcre is gone from the
workspace along with its LICENSE entry.

The forwards expand as they read: isMatch becomes
preg_match2(.., 0).is_some() (is_none() where PHP negates it), isMatch3
and match3 drop the .is_some(), matchAll counts through
preg_match_all2(..).occurrence_count(), and replace4/replace5 spell out
the limit and count arguments preg_replace2 takes. Callbacks are the one
place the shapes differ: preg_replace_callback carries an error out of
the callback, so the fourteen infallible closures wrap their result in
Ok() and expect() it back.

Config::process() is the fifteenth, and it drops the `error` cell it
captured to smuggle a failure past a closure that could only return a
String. The `?` in the closure now carries it, which is what the PHP
does -- a throw from the callback leaves preg_replace_callback at the
failing match rather than running the remaining replacements and
reporting the last error.

The module doc that explained why composer/pcre's exceptions and
*StrictGroups() variants have no counterpart moves to the shim's preg
module, where the functions it describes live.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/crates/shirabe/src/composer.rs b/crates/shirabe/src/composer.rs
index 1c6bbaed..6d3c6e26 100644
--- a/crates/shirabe/src/composer.rs
+++ b/crates/shirabe/src/composer.rs
@@ -11,8 +11,7 @@ use crate::package::{LockerInterface, RootPackageInterfaceHandle};
 use crate::plugin::PluginManager;
 use crate::repository::RepositoryManagerInterface;
 use crate::util::r#loop::Loop;
-use shirabe_pcre::Preg;
-use shirabe_php_shim::php_regex;
+use shirabe_php_shim::{php_regex, preg_match2};
 
 /// The Composer version this port tracks. Kept as-is so `Composer::VERSION`, the `composer`
 /// platform package and the HTTP User-Agent keep reporting a value plugins and servers can
@@ -43,7 +42,9 @@ pub fn get_version() -> String {
     if VERSION == "@package_version@" {
         return SOURCE_VERSION.to_string();
     }
-    if !BRANCH_ALIAS_VERSION.is_empty() && Preg::is_match(php_regex!("{^[a-f0-9]{40}$}"), VERSION) {
+    if !BRANCH_ALIAS_VERSION.is_empty()
+        && preg_match2(php_regex!("{^[a-f0-9]{40}$}"), VERSION, 0).is_some()
+    {
         return format!("{}+{}", BRANCH_ALIAS_VERSION, VERSION);
     }
     VERSION.to_string()