feat(plugin): widen the RPC surface to LibraryInstaller-based plugins

An installer that extends LibraryInstaller reaches for the Composer object
graph in ways the proxy did not answer: the download manager and the config,
the writable repository methods, a React promise as its own return value, and
`new Package(...)` from its supports() path.

* `Composer::getConfig`/`getDownloadManager` are dispatched, and both classes
  become generated proxy stubs. Their reads and mutators answer from the Rust
  entity; the surfaces needing stubs of their own (ConfigSourceInterface,
  DownloaderInterface) stay explicit errors.
* The download manager's futures are driven to completion and handed back as
  already-settled React promises, since PHP declares a non-nullable
  PromiseInterface there. A promise a plugin returns is drained the same way:
  settled yields its value, rejected re-raises, pending is an explicit error.
* Proxy stubs now carry the real class's constructor and ask the Rust side to
  allocate the entity; reviving a stub for an existing entity binds the handle
  without running it. Classes Rust cannot build name themselves in the error.
* The package proxy covers `Package`'s own setters, `CompletePackage`'s
  metadata, `RootPackage`'s root-only state, and `BasePackage::$id`.

Link values and release dates still have no wire image, so the methods
carrying them remain explicit errors.

3 files changed, 29 insertions, 9 deletions

diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/IO/BaseIO.php b/crates/shirabe-php-rpc/php/stubs/Composer/IO/BaseIO.php
index b3e0fb51..ecb4db2f 100644
--- a/crates/shirabe-php-rpc/php/stubs/Composer/IO/BaseIO.php
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/IO/BaseIO.php
@@ -14,16 +14,12 @@ abstract class BaseIO implements IOInterface, \ShirabeRustStub
     /** @var int */
     protected $__epoch;
 
-    public function __construct(int $rhandle = 0, int $epoch = 0)
+    /**
+     * 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
     {
-        if (func_num_args() < 2) {
-            // Constructing the class from plugin code (a common idiom for e.g. `new BufferIO()`)
-            // is an open question of the plugin design; only proxy instantiation passes a
-            // Rust handle. Fail with a diagnosable message instead of an ArgumentCountError.
-            throw new \RuntimeException(
-                'Shirabe does not support constructing ' . static::class . ' inside the plugin process yet'
-            );
-        }
         $this->__rhandle = $rhandle;
         $this->__epoch = $epoch;
     }
@@ -52,6 +48,12 @@ abstract class BaseIO implements IOInterface, \ShirabeRustStub
         \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
     }
 
+    public function __construct()
+    {
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust(0, '__shirabeConstruct', [static::class, []]);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
     public function isInteractive()
     {
         return \ShirabeRpcRuntime::callRust($this->__rhandle, 'isInteractive', []);
diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/IO/BufferIO.php b/crates/shirabe-php-rpc/php/stubs/Composer/IO/BufferIO.php
index d5e59e90..b2e84d2b 100644
--- a/crates/shirabe-php-rpc/php/stubs/Composer/IO/BufferIO.php
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/IO/BufferIO.php
@@ -5,8 +5,17 @@
 
 namespace Composer\IO;
 
+use Symfony\Component\Console\Output\StreamOutput;
+use Symfony\Component\Console\Formatter\OutputFormatterInterface;
+
 class BufferIO extends ConsoleIO
 {
+    public function __construct(string $input = '', int $verbosity = StreamOutput::VERBOSITY_NORMAL, ?OutputFormatterInterface $formatter = null)
+    {
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust(0, '__shirabeConstruct', [static::class, [$input, $verbosity, $formatter]]);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
     public function getOutput(): string
     {
         return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getOutput', []);
diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/IO/ConsoleIO.php b/crates/shirabe-php-rpc/php/stubs/Composer/IO/ConsoleIO.php
index 0041363a..b68f50ff 100644
--- a/crates/shirabe-php-rpc/php/stubs/Composer/IO/ConsoleIO.php
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/IO/ConsoleIO.php
@@ -6,10 +6,19 @@
 namespace Composer\IO;
 
 use Composer\Pcre\Preg;
+use Symfony\Component\Console\Helper\HelperSet;
 use Symfony\Component\Console\Helper\Table;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
 
 class ConsoleIO extends BaseIO
 {
+    public function __construct(InputInterface $input, OutputInterface $output, HelperSet $helperSet)
+    {
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust(0, '__shirabeConstruct', [static::class, [$input, $output, $helperSet]]);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
     public static function sanitize($messages, bool $allowNewlines = true)
     {
         // Match ANSI escape sequences: