feat(plugin-class-classifier): add deterministic plugin-boundary classifier

Decides, for every composer/composer class, how it is treated at the
plugin boundary (rust-proxy / rust-snapshot / contract / two-world /
php-native / unsupported) so that upstream updates re-classify new or
rewritten classes without re-deriving the design by hand. Rules and
category definitions live in docs/dev/plugin-class-classification.md;
the tool (PHP + nikic/PHP-Parser) implements them as a reachability
closure with direction marks, per-method pure/mutator analysis, and a
leaf-first fixed point for unreachable classes, with three small
versioned exception lists.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/scripts/plugin-class-classifier/lists/static-state.list b/scripts/plugin-class-classifier/lists/static-state.list
new file mode 100644
index 00000000..a33faeec
--- /dev/null
+++ b/scripts/plugin-class-classifier/lists/static-state.list
@@ -0,0 +1,21 @@
+# Disposition of classes that write static properties.
+#   memo-cache  pure memoization; each world computes its own copy
+#   seed-once   copied from the Rust side once at child startup
+#   needs-sync  genuinely shared process state; must not be php-native
+# A class writing statics without an entry here fails the run.
+Composer\Autoload\ClassLoader memo-cache
+Composer\Cache memo-cache
+Composer\Downloader\FileDownloader needs-sync
+Composer\Downloader\ZipDownloader memo-cache
+Composer\InstalledVersions needs-sync
+Composer\Package\Version\VersionParser memo-cache
+Composer\Platform\HhvmDetector memo-cache
+Composer\Repository\PlatformRepository memo-cache
+Composer\Util\ErrorHandler memo-cache
+Composer\Util\Git memo-cache
+Composer\Util\Hg memo-cache
+Composer\Util\Http\ProxyManager memo-cache
+Composer\Util\Platform needs-sync
+Composer\Util\ProcessExecutor seed-once
+Composer\Util\Silencer memo-cache
+Composer\Util\Svn memo-cache