✨ Add OAuth functionality, MCP tools, and feature tests

- 🔒 Added migrations for `oauth_access_tokens`, `oauth_refresh_tokens`, `oauth_auth_codes`, `oauth_clients`, and `oauth_device_codes`.
- 🤖 Created MCP tools (Meetups, Cities, Venues, Courses, Lecturers) for managing entities with authentication and validation.
- 🛠️ Implemented Passport-backed OAuth API guard configuration and validation endpoints.
- ✅ Added comprehensive feature tests for MCP tools and OAuth functionality (access control, validation, and token-based authentication).

app/Mcp/Tools/Lecturer/ShowMyLecturerTool.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Mcp\Tools\Lecturer;
+
+use App\Http\Resources\LecturerResource;
+use App\Models\Lecturer;
+use Illuminate\Contracts\JsonSchema\JsonSchema;
+use Illuminate\JsonSchema\Types\Type;
+use Illuminate\Support\Facades\Gate;
+use Laravel\Mcp\Request;
+use Laravel\Mcp\Response;
+use Laravel\Mcp\Server\Attributes\Description;
+use Laravel\Mcp\Server\Tool;
+use Laravel\Mcp\Server\Tools\Annotations\IsReadOnly;
+
+#[IsReadOnly]
+#[Description('Zeigt einen einzelnen, vom authentifizierten Nutzer erstellten Referenten.')]
+class ShowMyLecturerTool extends Tool
+{
+    public function handle(Request $request): Response
+    {
+        $lecturer = Lecturer::find($request->get('id'));
+
+        if (! $lecturer) {
+            return Response::error('Referent nicht gefunden.');
+        }
+
+        $user = $request->user();
+
+        if ($user === null || Gate::forUser($user)->denies('view', $lecturer)) {
+            return Response::error('Nur der Ersteller oder ein Super-Admin darf diesen Referenten sehen.');
+        }
+
+        return Response::json(LecturerResource::make($lecturer)->resolve());
+    }
+
+    /**
+     * @return array<string, Type>
+     */
+    public function schema(JsonSchema $schema): array
+    {
+        return [
+            'id' => $schema->integer()->description('ID des Referenten.')->required(),
+        ];
+    }
+}