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, 126 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Request.php b/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Request.php
new file mode 100644
index 00000000..2d472d18
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Request.php
@@ -0,0 +1,126 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Guard for Composer\DependencyResolver\Request.
+// 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\DependencyResolver;
+
+use Composer\Package\BasePackage;
+use Composer\Package\PackageInterface;
+use Composer\Repository\LockArrayRepository;
+use Composer\Semver\Constraint\ConstraintInterface;
+
+class Request
+{
+    public const UPDATE_ONLY_LISTED = 0;
+    public const UPDATE_LISTED_WITH_TRANSITIVE_DEPS_NO_ROOT_REQUIRE = 1;
+    public const UPDATE_LISTED_WITH_TRANSITIVE_DEPS = 2;
+
+    public function __construct(?LockArrayRepository $lockedRepository = null)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, '__construct');
+    }
+
+    public function requireName(string $packageName, ?ConstraintInterface $constraint = null): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'requireName');
+    }
+
+    public function fixPackage(BasePackage $package): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'fixPackage');
+    }
+
+    public function lockPackage(BasePackage $package): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'lockPackage');
+    }
+
+    public function fixLockedPackage(BasePackage $package): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'fixLockedPackage');
+    }
+
+    public function unlockPackage(BasePackage $package): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'unlockPackage');
+    }
+
+    public function setUpdateAllowList(array $updateAllowList, $updateAllowTransitiveDependencies): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setUpdateAllowList');
+    }
+
+    public function getUpdateAllowList(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getUpdateAllowList');
+    }
+
+    public function getUpdateAllowTransitiveDependencies(): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getUpdateAllowTransitiveDependencies');
+    }
+
+    public function getUpdateAllowTransitiveRootDependencies(): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getUpdateAllowTransitiveRootDependencies');
+    }
+
+    public function getRequires(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getRequires');
+    }
+
+    public function getFixedPackages(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFixedPackages');
+    }
+
+    public function isFixedPackage(BasePackage $package): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isFixedPackage');
+    }
+
+    public function getLockedPackages(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getLockedPackages');
+    }
+
+    public function isLockedPackage(PackageInterface $package): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isLockedPackage');
+    }
+
+    public function getFixedOrLockedPackages(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFixedOrLockedPackages');
+    }
+
+    public function getPresentMap(bool $packageIds = false): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPresentMap');
+    }
+
+    public function getFixedPackagesMap(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFixedPackagesMap');
+    }
+
+    public function getLockedRepository(): ?LockArrayRepository
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getLockedRepository');
+    }
+
+    public function restrictPackages(array $names): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'restrictPackages');
+    }
+
+    public function getRestrictedPackages(): ?array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getRestrictedPackages');
+    }
+}