feat(php-rpc): rework the RPC channel into the tagged plugin protocol

Replace the name\0arg framing with the plugin wire protocol: tagged
frames with corr_id multiplexing, a MAX_FRAME_LEN bound, a thread-ID
based reentrant SessionLock, and the PluginValue codec (encoder plus
the first recursive decoder, iterative with a 512-level depth cap).
Float formatting is ported from php-src into shirabe-php-src so the
encoder is byte-compatible with serialize() under serialize_precision=-1,
which the spawned worker now pins. The worker gains a standing dispatch
loop, CallRustMethod reentrancy, hand-written Event proxy stubs, and
explicit-error answers for everything not implemented yet. The public
query API (get_php_version and friends) is unchanged and now rides the
new protocol; the codec is verified against real PHP by roundtrip
oracle tests covering floats, non-UTF-8 bytes and deep nesting.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/Script/Event.php b/crates/shirabe-php-rpc/php/stubs/Composer/Script/Event.php
new file mode 100644
index 00000000..80afe1b7
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/Script/Event.php
@@ -0,0 +1,37 @@
+<?php
+
+// Hand-written proxy stub for Composer\Script\Event, kept in the shape the future stub
+// generator will output. See Composer/EventDispatcher/Event.php.
+
+namespace Composer\Script;
+
+use Composer\EventDispatcher\Event as BaseEvent;
+
+class Event extends BaseEvent
+{
+    public function getComposer(): \Composer\Composer
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getComposer', []);
+    }
+
+    public function getIO(): \Composer\IO\IOInterface
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getIO', []);
+    }
+
+    public function isDevMode(): bool
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'isDevMode', []);
+    }
+
+    public function getOriginatingEvent(): ?BaseEvent
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getOriginatingEvent', []);
+    }
+
+    public function setOriginatingEvent(BaseEvent $event): self
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'setOriginatingEvent', [$event]);
+        return $this;
+    }
+}