✨ 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/Course/CreateCourseTool.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace App\Mcp\Tools\Course;
+
+use App\Models\Course;
+use App\Models\User;
+use Illuminate\Contracts\JsonSchema\JsonSchema;
+use Illuminate\JsonSchema\Types\Type;
+use Laravel\Mcp\Request;
+use Laravel\Mcp\Response;
+use Laravel\Mcp\Server\Attributes\Description;
+use Laravel\Mcp\Server\Tool;
+
+#[Description('Legt einen neuen Kurs für den authentifizierten Referenten an. Der Ersteller (created_by) wird automatisch gesetzt.')]
+class CreateCourseTool extends Tool
+{
+    public function handle(Request $request): Response
+    {
+        $user = $request->user();
+
+        if (! $user instanceof User || ! (bool) $user->is_lecturer) {
+            return Response::error('Nur Referenten (is_lecturer) dürfen Kurse anlegen.');
+        }
+
+        $validated = $request->validate([
+            'name' => ['required', 'string', 'max:255'],
+            'lecturer_id' => ['required', 'exists:lecturers,id'],
+            'description' => ['nullable', 'string'],
+        ]);
+
+        $course = Course::create($validated);
+
+        return Response::json($course->fresh());
+    }
+
+    /**
+     * @return array<string, Type>
+     */
+    public function schema(JsonSchema $schema): array
+    {
+        return [
+            'name' => $schema->string()->description('Name des Kurses.')->required(),
+            'lecturer_id' => $schema->integer()->description('ID des zugehörigen Referenten (vorher per search-lecturers auflösen).')->required(),
+            'description' => $schema->string()->description('Beschreibung des Kurses.'),
+        ];
+    }
+}