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, 219 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/Util/Perforce.php b/crates/shirabe-php-rpc/php/guards/Composer/Util/Perforce.php
new file mode 100644
index 00000000..892317b9
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/guards/Composer/Util/Perforce.php
@@ -0,0 +1,219 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Guard for Composer\Util\Perforce.
+// 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\Util;
+
+use Composer\IO\IOInterface;
+
+class Perforce
+{
+    public function __construct($repoConfig, string $port, string $path, ProcessExecutor $process, bool $isWindows, IOInterface $io)
+    {
+        \ShirabeUnsupportedClass::fail(self::class, '__construct');
+    }
+
+    public static function create($repoConfig, string $port, string $path, ProcessExecutor $process, IOInterface $io): self
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'create');
+    }
+
+    public static function checkServerExists(string $url, ProcessExecutor $processExecutor): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'checkServerExists');
+    }
+
+    public function initialize($repoConfig): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'initialize');
+    }
+
+    public function initializeDepotAndBranch(?string $depot, ?string $branch): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'initializeDepotAndBranch');
+    }
+
+    public function generateUniquePerforceClientName(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'generateUniquePerforceClientName');
+    }
+
+    public function cleanupClientSpec(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'cleanupClientSpec');
+    }
+
+    protected function executeCommand($command): int
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'executeCommand');
+    }
+
+    public function getClient(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getClient');
+    }
+
+    protected function getPath(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPath');
+    }
+
+    public function initializePath(string $path): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'initializePath');
+    }
+
+    protected function getPort(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getPort');
+    }
+
+    public function setStream(string $stream): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setStream');
+    }
+
+    public function isStream(): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isStream');
+    }
+
+    public function getStream(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getStream');
+    }
+
+    public function getStreamWithoutLabel(string $stream): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getStreamWithoutLabel');
+    }
+
+    public function getP4ClientSpec(): string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getP4ClientSpec');
+    }
+
+    public function getUser(): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getUser');
+    }
+
+    public function setUser(?string $user): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setUser');
+    }
+
+    public function queryP4User(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'queryP4User');
+    }
+
+    protected function getP4variable(string $name): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getP4variable');
+    }
+
+    public function queryP4Password(): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'queryP4Password');
+    }
+
+    public function generateP4Command(array $arguments, bool $useClient = true): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'generateP4Command');
+    }
+
+    public function isLoggedIn(): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'isLoggedIn');
+    }
+
+    public function connectClient(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'connectClient');
+    }
+
+    public function syncCodeBase(?string $sourceReference): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'syncCodeBase');
+    }
+
+    public function writeClientSpecToFile($spec): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'writeClientSpecToFile');
+    }
+
+    public function writeP4ClientSpec(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'writeP4ClientSpec');
+    }
+
+    protected function read($pipe, $name): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'read');
+    }
+
+    public function windowsLogin(?string $password): int
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'windowsLogin');
+    }
+
+    public function p4Login(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'p4Login');
+    }
+
+    public function getComposerInformation(string $identifier): ?array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getComposerInformation');
+    }
+
+    public function getFileContent(string $file, string $identifier): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFileContent');
+    }
+
+    public function getFilePath(string $file, string $identifier): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFilePath');
+    }
+
+    public function getBranches(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getBranches');
+    }
+
+    public function getTags(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getTags');
+    }
+
+    public function checkStream(): bool
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'checkStream');
+    }
+
+    protected function getChangeList(string $reference): mixed
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getChangeList');
+    }
+
+    public function getCommitLogs(string $fromReference, string $toReference): mixed
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getCommitLogs');
+    }
+
+    public function getFilesystem(): Filesystem
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getFilesystem');
+    }
+
+    public function setFilesystem(Filesystem $fs): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'setFilesystem');
+    }
+}