✨ 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/Venue/CreateVenueTool.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Mcp\Tools\Venue;
+
+use App\Http\Requests\Api\StoreVenueRequest;
+use App\Http\Resources\VenueResource;
+use App\Models\Venue;
+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;
+
+#[Description('Legt einen neuen Veranstaltungsort (Venue) für den authentifizierten Nutzer an. Der Ersteller (created_by) wird automatisch gesetzt.')]
+class CreateVenueTool extends Tool
+{
+    public function handle(Request $request): Response
+    {
+        $user = $request->user();
+
+        if ($user === null || Gate::forUser($user)->denies('create', Venue::class)) {
+            return Response::error('Nicht berechtigt, einen Veranstaltungsort anzulegen.');
+        }
+
+        $storeRequest = new StoreVenueRequest;
+
+        $validated = $request->validate(
+            $storeRequest->rules(),
+            $storeRequest->messages(),
+        );
+
+        $venue = Venue::create($validated);
+
+        return Response::json(VenueResource::make($venue->fresh())->resolve());
+    }
+
+    /**
+     * @return array<string, Type>
+     */
+    public function schema(JsonSchema $schema): array
+    {
+        return [
+            'city_id' => $schema->integer()->description('ID der zugehörigen Stadt (vorher per search-cities auflösen).')->required(),
+            'name' => $schema->string()->description('Name des Veranstaltungsorts.')->required(),
+            'street' => $schema->string()->description('Straße und Hausnummer des Veranstaltungsorts.')->required(),
+        ];
+    }
+}