feat(plugin): serve Loop as a proxy stub

Composer::getLoop() answers, so a plugin reaches the graph's own downloader
and executor through the route Composer's own docblocks point plugin authors
at, rather than through an instance of its own.

wait() drains the promises it is given and rethrows the first rejection once
the group is done, which is what React\Promise\all() hands PHP. abortJobs()
has nothing to cancel while every request settles before the call that
started it returns. A non-null $progress is an explicit error: a ProgressBar
is a symfony/console object each world runs its own implementation of, so
there is none to hand across.

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

2 files changed, 96 insertions, 39 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/Util/Loop.php b/crates/shirabe-php-rpc/php/guards/Composer/Util/Loop.php
deleted file mode 100644
index 32648ece..00000000
--- a/crates/shirabe-php-rpc/php/guards/Composer/Util/Loop.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-// Generated by scripts/plugin-stub-generator; do not edit by hand.
-// Guard for Composer\Util\Loop.
-// 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 Symfony\Component\Console\Helper\ProgressBar;
-
-class Loop
-{
-    public function __construct(HttpDownloader $httpDownloader, ?ProcessExecutor $processExecutor = null)
-    {
-        \ShirabeUnsupportedClass::fail(self::class, '__construct');
-    }
-
-    public function getHttpDownloader(): HttpDownloader
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getHttpDownloader');
-    }
-
-    public function getProcessExecutor(): ?ProcessExecutor
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getProcessExecutor');
-    }
-
-    public function wait(array $promises, ?ProgressBar $progress = null): void
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'wait');
-    }
-
-    public function abortJobs(): void
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'abortJobs');
-    }
-}
diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/Util/Loop.php b/crates/shirabe-php-rpc/php/stubs/Composer/Util/Loop.php
new file mode 100644
index 00000000..61e6edfe
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/Util/Loop.php
@@ -0,0 +1,96 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Proxy stub for Composer\Util\Loop: the public surface forwards to the Rust-side entity over RPC.
+
+namespace Composer\Util;
+
+use Symfony\Component\Console\Helper\ProgressBar;
+
+class Loop implements \ShirabeRustStub
+{
+    /** @var int */
+    protected $__rhandle;
+    /** @var int */
+    protected $__epoch;
+
+    /**
+     * Binds a stub the registry built for an existing entity. Proxy instantiation bypasses
+     * the constructor, which belongs to plugin code building a new entity instead.
+     */
+    public function __shirabeBind(int $rhandle, int $epoch): void
+    {
+        $this->__rhandle = $rhandle;
+        $this->__epoch = $epoch;
+    }
+
+    public function __destruct()
+    {
+        \ShirabeRustObjectRegistry::release($this->__rhandle);
+    }
+
+    public function __shirabeRustHandleDescriptor(): array
+    {
+        return [
+            '__rhandle' => $this->__rhandle,
+            '__class' => static::class,
+            '__epoch' => $this->__epoch,
+        ];
+    }
+
+    public function __clone()
+    {
+        // PHP has already shallow-copied this stub, so both copies would point at one
+        // entity and release it twice. The Rust side clones the entity instead, applying
+        // whatever __clone semantics the real class defines, and this copy rebinds to the
+        // fresh handle. Entities without clone semantics answer with an explicit error.
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust($this->__rhandle, '__shirabeClone', []);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
+    public function __get($name)
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, '__get', [$name]);
+    }
+
+    public function __set($name, $value): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, '__set', [$name, $value]);
+    }
+
+    public function __isset($name): bool
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, '__isset', [$name]);
+    }
+
+    public function __unset($name): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, '__unset', [$name]);
+    }
+
+    public function __construct(HttpDownloader $httpDownloader, ?ProcessExecutor $processExecutor = null)
+    {
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust(0, '__shirabeConstruct', [static::class, [$httpDownloader, $processExecutor]]);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
+    public function getHttpDownloader(): HttpDownloader
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getHttpDownloader', []);
+    }
+
+    public function getProcessExecutor(): ?ProcessExecutor
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getProcessExecutor', []);
+    }
+
+    public function wait(array $promises, ?ProgressBar $progress = null): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'wait', [$promises, $progress]);
+    }
+
+    public function abortJobs(): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'abortJobs', []);
+    }
+}