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, 115 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Pool.php b/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Pool.php
new file mode 100644
index 00000000..a1770817
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/guards/Composer/DependencyResolver/Pool.php
@@ -0,0 +1,115 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Guard for Composer\DependencyResolver\Pool.
+// 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\Semver\Constraint\ConstraintInterface;
+
+class Pool implements \Countable
+{
+    public function __construct(array $packages = [], array $unacceptableFixedOrLockedPackages = [], array $removedVersions = [], array $removedVersionsByPackage = [], array $securityRemovedVersions = [], array $abandonedRemovedVersions = [])
+    {
+        \ShirabeUnsupportedClass::fail(self::class, '__construct');
+    }
+
+    public function getRemovedVersions(string $name, ConstraintInterface $constraint): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getRemovedVersions');
+    }
+
+    public function getAllRemovedVersions(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAllRemovedVersions');
+    }
+
+    public function getRemovedVersionsByPackage(string $objectHash): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getRemovedVersionsByPackage');
+    }
+
+    public function getAllRemovedVersionsByPackage(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAllRemovedVersionsByPackage');
+    }
+
+    public function isSecurityRemovedPackageVersion(string $packageName, ?ConstraintInterface $constraint): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isSecurityRemovedPackageVersion');
+    }
+
+    public function getSecurityAdvisoryIdentifiersForPackageVersion(string $packageName, ?ConstraintInterface $constraint): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getSecurityAdvisoryIdentifiersForPackageVersion');
+    }
+
+    public function isAbandonedRemovedPackageVersion(string $packageName, ?ConstraintInterface $constraint): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isAbandonedRemovedPackageVersion');
+    }
+
+    public function getAllSecurityRemovedPackageVersions(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAllSecurityRemovedPackageVersions');
+    }
+
+    public function getAllAbandonedRemovedPackageVersions(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getAllAbandonedRemovedPackageVersions');
+    }
+
+    public function getPackages(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPackages');
+    }
+
+    public function packageById(int $id): BasePackage
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'packageById');
+    }
+
+    public function count(): int
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'count');
+    }
+
+    public function whatProvides(string $name, ?ConstraintInterface $constraint = null): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'whatProvides');
+    }
+
+    public function literalToPackage(int $literal): BasePackage
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'literalToPackage');
+    }
+
+    public function literalToPrettyString(int $literal, array $installedMap): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'literalToPrettyString');
+    }
+
+    public function match(BasePackage $candidate, string $name, ?ConstraintInterface $constraint = null): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'match');
+    }
+
+    public function isUnacceptableFixedOrLockedPackage(BasePackage $package): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isUnacceptableFixedOrLockedPackage');
+    }
+
+    public function getUnacceptableFixedOrLockedPackages(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getUnacceptableFixedOrLockedPackages');
+    }
+
+    public function __toString(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, '__toString');
+    }
+}