Fix bin/publish: copy docs.dist from project root

Fix bin/publish: use correct .env path for rspade_system
Fix bin/publish script: prevent grep exit code 1 from terminating script

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

vendor/guzzlehttp/promises/src/Is.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GuzzleHttp\Promise;
+
+final class Is
+{
+    /**
+     * Returns true if a promise is pending.
+     */
+    public static function pending(PromiseInterface $promise): bool
+    {
+        return $promise->getState() === PromiseInterface::PENDING;
+    }
+
+    /**
+     * Returns true if a promise is fulfilled or rejected.
+     */
+    public static function settled(PromiseInterface $promise): bool
+    {
+        return $promise->getState() !== PromiseInterface::PENDING;
+    }
+
+    /**
+     * Returns true if a promise is fulfilled.
+     */
+    public static function fulfilled(PromiseInterface $promise): bool
+    {
+        return $promise->getState() === PromiseInterface::FULFILLED;
+    }
+
+    /**
+     * Returns true if a promise is rejected.
+     */
+    public static function rejected(PromiseInterface $promise): bool
+    {
+        return $promise->getState() === PromiseInterface::REJECTED;
+    }
+}