Add API documentation generation with phpDocumentor (#184)

* Add API documentation generation with phpDocumentor

- Add phpDocumentor configuration and `docs` Makefile target
- Generate docs during CI to catch errors before releases
- Set up GitHub Pages with Jekyll for hosting generated docs
- Add GitHub Actions workflow to deploy docs to GitHub Pages on releases

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix phpDocumentor errors in type annotations

Change class-string union types to use phpDocumentor-compatible syntax
and reorder docblock tags so class descriptions precede `@author` tags.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix CI: pin phar-io/composer-distributor ^1.0.2

phar-io/composer-distributor 1.0.0 has a bug where it uses the wrong
package version when determining the phpDocumentor download URL,
causing CI to fail with 404 errors when using --prefer-lowest.
Version 1.0.2 fixes this issue.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Integrate markdown guides into phpDocumentor output

Configure phpDocumentor to generate both API documentation and user
guides in a single unified site. This replaces the previous Jekyll-based
approach where API docs were copied into the docs folder.

- Add `<guide>` configuration to `phpdoc.dist.xml`
- Create custom template with "Guides" navigation link
- Replace `docs/index.html` redirect with `docs/index.md` guide index
- Update workflow to publish `build/docs` directly without Jekyll
- Track `.phpdoc/template/` while still ignoring `.phpdoc/cache/`

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fine-tuning for path, config, and layout

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>

src/JsonRpc/MessageFactory.php

@@ -37,7 +37,7 @@ final class MessageFactory
     /**
      * Registry of all known message classes that have methods.
      *
-     * @var array<int, class-string<Request|Notification>>
+     * @var list<class-string<Request>|class-string<Notification>>
      */
     private const REGISTERED_MESSAGES = [
         Schema\Notification\CancelledNotification::class,
@@ -68,7 +68,7 @@ final class MessageFactory
     ];
 
     /**
-     * @param array<int, class-string<Request|Notification>> $registeredMessages
+     * @param list<class-string<Request>|class-string<Notification>> $registeredMessages
      */
     public function __construct(
         private readonly array $registeredMessages,
@@ -151,7 +151,7 @@ final class MessageFactory
     /**
      * Finds the registered message class for a given method name.
      *
-     * @return class-string<Request|Notification>
+     * @return class-string<Request>|class-string<Notification>
      *
      * @throws InvalidInputMessageException
      */

src/Server/Session/Psr16StoreSession.php

@@ -17,12 +17,12 @@ use Psr\SimpleCache\CacheInterface;
 use Symfony\Component\Uid\Uuid;
 
 /**
- * @author luoyue <1569097443@qq.com>
- *
  * PSR-16 compliant cache-based session store.
  *
  * This implementation uses any PSR-16 compliant cache as the storage backend
  * for session data. Each session is stored with a prefixed key using the session ID.
+ *
+ * @author luoyue <1569097443@qq.com>
  */
 class Psr16StoreSession implements SessionStoreInterface
 {