feat(plugin): carry Http\Response across as a materialized value

A response is built for one request and the graph never retains it, so there
is no entity for a handle to point at. The child holds a real instance
instead, revived from the object record the wire carries, and collect() frees
the copy each world holds — which is what that method is for. The
value-object rule rejects the class only because collect() assigns to $this,
so the category comes from an overrides.list entry.

HttpDownloader::get() and copy() answer with one.

Two gaps stay: decodeJson() reaches Composer\Json\JsonFile, which a guard
shadows, and Composer answers a curl request with the CurlResponse subclass
where this port flattens the value into a Response.

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

3 files changed, 42 insertions, 57 deletions

diff --git a/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/CurlResponse.php b/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/CurlResponse.php
index ae229589..ffb000f3 100644
--- a/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/CurlResponse.php
+++ b/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/CurlResponse.php
@@ -19,4 +19,44 @@ class CurlResponse extends Response
     {
         \ShirabeUnsupportedClass::fail(self::class, 'getCurlInfo');
     }
+
+    public function getStatusCode(): int
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getStatusCode');
+    }
+
+    public function getStatusMessage(): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getStatusMessage');
+    }
+
+    public function getHeaders(): array
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getHeaders');
+    }
+
+    public function getHeader(string $name): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getHeader');
+    }
+
+    public function getBody(): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'getBody');
+    }
+
+    public function decodeJson()
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'decodeJson');
+    }
+
+    public function collect(): void
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'collect');
+    }
+
+    public static function findHeaderValue(array $headers, string $name): ?string
+    {
+        \ShirabeUnsupportedClass::fail(self::class, 'findHeaderValue');
+    }
 }
diff --git a/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/Response.php b/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/Response.php
deleted file mode 100644
index 61eebb7f..00000000
--- a/crates/shirabe-php-rpc/php/guards/Composer/Util/Http/Response.php
+++ /dev/null
@@ -1,57 +0,0 @@
-<?php
-
-// Generated by scripts/plugin-stub-generator; do not edit by hand.
-// Guard for Composer\Util\Http\Response.
-// 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\Http;
-
-class Response
-{
-    public function __construct(array $request, ?int $code, array $headers, ?string $body)
-    {
-        \ShirabeUnsupportedClass::fail(self::class, '__construct');
-    }
-
-    public function getStatusCode(): int
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getStatusCode');
-    }
-
-    public function getStatusMessage(): ?string
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getStatusMessage');
-    }
-
-    public function getHeaders(): array
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getHeaders');
-    }
-
-    public function getHeader(string $name): ?string
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getHeader');
-    }
-
-    public function getBody(): ?string
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'getBody');
-    }
-
-    public function decodeJson()
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'decodeJson');
-    }
-
-    public function collect(): void
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'collect');
-    }
-
-    public static function findHeaderValue(array $headers, string $name): ?string
-    {
-        \ShirabeUnsupportedClass::fail(self::class, 'findHeaderValue');
-    }
-}
diff --git a/crates/shirabe-php-rpc/php/runtime/Shirabe/MaterializedValue.php b/crates/shirabe-php-rpc/php/runtime/Shirabe/MaterializedValue.php
index c16b4e18..73a12033 100644
--- a/crates/shirabe-php-rpc/php/runtime/Shirabe/MaterializedValue.php
+++ b/crates/shirabe-php-rpc/php/runtime/Shirabe/MaterializedValue.php
@@ -17,6 +17,7 @@ use Composer\Semver\Constraint\Constraint;
 use Composer\Semver\Constraint\MatchAllConstraint;
 use Composer\Semver\Constraint\MatchNoneConstraint;
 use Composer\Semver\Constraint\MultiConstraint;
+use Composer\Util\Http\Response;
 
 final class MaterializedValue
 {
@@ -26,6 +27,7 @@ final class MaterializedValue
         MultiConstraint::class,
         MatchAllConstraint::class,
         MatchNoneConstraint::class,
+        Response::class,
         \DateTimeImmutable::class,
         \DateTime::class,
     ];