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>

3 files changed, 13 insertions, 15 deletions

diff --git a/crates/shirabe/src/io/base_io.rs b/crates/shirabe/src/io/base_io.rs
index 4d0d9309..08a9fd7e 100644
--- a/crates/shirabe/src/io/base_io.rs
+++ b/crates/shirabe/src/io/base_io.rs
@@ -6,10 +6,9 @@ use crate::io::io_interface;
 use crate::util::ProcessExecutor;
 use crate::util::Silencer;
 use indexmap::IndexMap;
-use shirabe_pcre::Preg;
 use shirabe_php_shim::{
     JSON_INVALID_UTF8_IGNORE, JSON_UNESCAPED_SLASHES, JSON_UNESCAPED_UNICODE, PhpMixed,
-    UnexpectedValueException, array_merge, in_array_strict, json_encode_ex, php_regex,
+    UnexpectedValueException, array_merge, in_array_strict, json_encode_ex, php_regex, preg_match2,
 };
 
 /// ref: composer/vendor/psr/log/Psr/Log/LogLevel.php
@@ -157,7 +156,7 @@ pub trait BaseIO: IOInterface {
                     config.merge(&config_outer, "implicit-due-to-auth");
                 }
 
-                if !Preg::is_match(php_regex!(r"{^[.A-Za-z0-9_]+$}"), &token_str) {
+                if preg_match2(php_regex!(r"{^[.A-Za-z0-9_]+$}"), &token_str, 0).is_none() {
                     return Err(UnexpectedValueException::new(format!(
                         "Your github oauth token for {} contains invalid characters: \"{}\"",
                         domain, token_str
diff --git a/crates/shirabe/src/io/buffer_io.rs b/crates/shirabe/src/io/buffer_io.rs
index 466efe0b..3b1afdf8 100644
--- a/crates/shirabe/src/io/buffer_io.rs
+++ b/crates/shirabe/src/io/buffer_io.rs
@@ -1,10 +1,9 @@
 //! ref: composer/src/Composer/IO/BufferIO.php
 
 use crate::io::ConsoleIO;
-use shirabe_pcre::Preg;
 use shirabe_php_shim::{
-    PHP_EOL, PhpMixed, PhpResource, RuntimeException, SEEK_SET, fopen, fseek, fwrite, php_regex,
-    rewind, stream_get_contents, strip_tags,
+    PHP_EOL, PhpMixed, PhpResource, PregMatches, RuntimeException, SEEK_SET, fopen, fseek, fwrite,
+    php_regex, preg_replace_callback, rewind, stream_get_contents, strip_tags,
 };
 use shirabe_symfony_console::formatter::OutputFormatterInterface;
 use shirabe_symfony_console::helper::QuestionHelper;
@@ -74,23 +73,24 @@ impl BufferIO {
         // pass, so the replacement is applied to a fixpoint (each pass strictly shrinks the string).
         let mut output = output;
         loop {
-            let next = Preg::replace_callback(
+            let next = preg_replace_callback(
                 php_regex!(r"{(^|\n|\x08)(.+?)(\x08+)}"),
-                |matches: &shirabe_pcre::PregMatches| -> String {
+                |matches: &PregMatches| -> anyhow::Result<String> {
                     let g1 = matches.get(1).unwrap_or("");
                     let g2 = matches.get(2).unwrap_or("");
                     let g3 = matches.get(3).unwrap_or("");
                     let pre = strip_tags(g2);
 
                     if pre.len() == g3.len() {
-                        return g1.to_string();
+                        return Ok(g1.to_string());
                     }
 
                     // TODO reverse parse the string, skipping span tags and \033\[([0-9;]+)m(.*?)\033\[0m style blobs
-                    format!("{}{}\n", g1, g2.trim_end())
+                    Ok(format!("{}{}\n", g1, g2.trim_end()))
                 },
                 &output,
-            );
+            )
+            .expect("the replacement callback cannot fail");
             if next == output {
                 break;
             }
diff --git a/crates/shirabe/src/io/console_io.rs b/crates/shirabe/src/io/console_io.rs
index e9ca2048..e3ba68b3 100644
--- a/crates/shirabe/src/io/console_io.rs
+++ b/crates/shirabe/src/io/console_io.rs
@@ -9,10 +9,9 @@ use crate::io::io_interface;
 use crate::question::StrictConfirmationQuestion;
 use indexmap::IndexMap;
 use indexmap::indexmap;
-use shirabe_pcre::Preg;
 use shirabe_php_shim::{
-    PhpMixed, array_search, in_array_strict, is_array, is_string, microtime, str_repeat,
-    strip_tags, strlen,
+    PhpMixed, array_search, in_array_strict, is_array, is_string, microtime, preg_replace,
+    str_repeat, strip_tags, strlen,
 };
 use shirabe_symfony_console::helper::ProgressBar;
 use shirabe_symfony_console::helper::QuestionHelper;
@@ -237,7 +236,7 @@ impl ConsoleIO {
         };
         let messages = Self::ensure_valid_utf8(messages);
 
-        Preg::replace(&pattern, replacement, &messages)
+        preg_replace(&pattern, replacement, &messages)
     }
 
     /// Ensures a string is valid UTF-8, replacing invalid byte sequences with '?'