feat(plugin): guard Rust-owned classes the worker has no proxy for

The worker's autoloader fell through to the real Composer source for every
Rust-owned FQCN without a proxy stub, so plugin code doing `new Filesystem()`
or subclassing `LibraryInstaller` silently ran on a second instance the Rust
side never sees. An unimplemented part of the plugin API has to fail with an
explicit error naming it, not quietly work on a disconnected copy.

The stub generator now emits a guard class for each of those FQCNs: the real
declaration, hierarchy and constants, with every constructor and method
raising an explicit error. References satisfied by the declaration alone
(`instanceof`, `X::class`, `Link::TYPE_REQUIRE`) keep working. Two FQCNs stay
resolvable to the real class, each listed with the worker-side mechanism that
makes a natively constructed instance correct.

The error had nowhere to go: `Installer::run` dropped the `Result` of both
`dispatch_script` calls, so an exception from a listener ended in exit 0.
Both propagate now, the way the exception does upstream.

Three real-plugin E2E comparisons stop at a guard and are ignored, each
naming the class it needs.

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

1 files changed, 143 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/Autoload/AutoloadGenerator.php b/crates/shirabe-php-rpc/php/guards/Composer/Autoload/AutoloadGenerator.php
new file mode 100644
index 00000000..92b6edad
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/guards/Composer/Autoload/AutoloadGenerator.php
@@ -0,0 +1,143 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Guard for Composer\Autoload\AutoloadGenerator.
+// The Rust side owns this class and the worker has no proxy for it, so this
+// declaration shadows the real one: the constants and the hierarchy stay, while
+// constructing it or calling anything on it raises an explicit error.
+
+namespace Composer\Autoload;
+
+use Composer\Config;
+use Composer\EventDispatcher\EventDispatcher;
+use Composer\Filter\PlatformRequirementFilter\PlatformRequirementFilterInterface;
+use Composer\Installer\InstallationManager;
+use Composer\IO\IOInterface;
+use Composer\Package\PackageInterface;
+use Composer\Package\RootPackageInterface;
+use Composer\Repository\InstalledRepositoryInterface;
+use Composer\Util\Filesystem;
+use Composer\Package\Locker;
+
+class AutoloadGenerator
+{
+    public function __construct(EventDispatcher $eventDispatcher, ?IOInterface $io = null)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, '__construct');
+    }
+
+    public function setDevMode(bool $devMode = true)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setDevMode');
+    }
+
+    public function setClassMapAuthoritative(bool $classMapAuthoritative)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setClassMapAuthoritative');
+    }
+
+    public function setApcu(bool $apcu, ?string $apcuPrefix = null)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setApcu');
+    }
+
+    public function setRunScripts(bool $runScripts = true)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setRunScripts');
+    }
+
+    public function setDryRun(bool $dryRun = true): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setDryRun');
+    }
+
+    public function setIgnorePlatformRequirements($ignorePlatformReqs)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setIgnorePlatformRequirements');
+    }
+
+    public function setPlatformRequirementFilter(PlatformRequirementFilterInterface $platformRequirementFilter)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setPlatformRequirementFilter');
+    }
+
+    public function dump(Config $config, InstalledRepositoryInterface $localRepo, RootPackageInterface $rootPackage, InstallationManager $installationManager, string $targetDir, bool $scanPsrPackages = false, ?string $suffix = null, ?Locker $locker = null, bool $strictAmbiguous = false)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'dump');
+    }
+
+    public function buildPackageMap(InstallationManager $installationManager, PackageInterface $rootPackage, array $packages)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'buildPackageMap');
+    }
+
+    protected function validatePackage(PackageInterface $package)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'validatePackage');
+    }
+
+    public function parseAutoloads(array $packageMap, PackageInterface $rootPackage, $filteredDevPackages = false)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'parseAutoloads');
+    }
+
+    public function createLoader(array $autoloads, ?string $vendorDir = null)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'createLoader');
+    }
+
+    protected function getIncludePathsFile(array $packageMap, Filesystem $filesystem, string $basePath, string $vendorPath, string $vendorPathCode, string $appBaseDirCode)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getIncludePathsFile');
+    }
+
+    protected function getIncludeFilesFile(array $files, Filesystem $filesystem, string $basePath, string $vendorPath, string $vendorPathCode, string $appBaseDirCode)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getIncludeFilesFile');
+    }
+
+    protected function getPathCode(Filesystem $filesystem, string $basePath, string $vendorPath, string $path)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPathCode');
+    }
+
+    protected function getPlatformCheck(array $packageMap, $checkPlatform, array $devPackageNames)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPlatformCheck');
+    }
+
+    protected function getAutoloadFile(string $vendorPathToTargetDirCode, string $suffix)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAutoloadFile');
+    }
+
+    protected function getAutoloadRealFile(bool $useClassMap, bool $useIncludePath, ?string $targetDirLoader, bool $useIncludeFiles, string $vendorPathCode, string $appBaseDirCode, string $suffix, bool $useGlobalIncludePath, string $prependAutoloader, bool $checkPlatform)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAutoloadRealFile');
+    }
+
+    protected function getStaticFile(string $suffix, string $targetDir, string $vendorPath, string $basePath)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getStaticFile');
+    }
+
+    protected function parseAutoloadsType(array $packageMap, string $type, RootPackageInterface $rootPackage)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'parseAutoloadsType');
+    }
+
+    protected function getFileIdentifier(PackageInterface $package, string $path)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFileIdentifier');
+    }
+
+    protected function filterPackageMap(array $packageMap, RootPackageInterface $rootPackage)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'filterPackageMap');
+    }
+
+    protected function sortPackageMap(array $packageMap)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'sortPackageMap');
+    }
+}