✨ 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/Search/SearchCitiesTool.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace App\Mcp\Tools\Search;
+
+use App\Models\City;
+use Illuminate\Contracts\JsonSchema\JsonSchema;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\JsonSchema\Types\Type;
+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('Sucht Städte (öffentlich) und liefert id, name und das zugehörige Land, alphabetisch sortiert, begrenzt auf 10 Einträge. Dient zum Auflösen von city_id vor dem Anlegen von Datensätzen.')]
+class SearchCitiesTool extends Tool
+{
+    public function handle(Request $request): Response
+    {
+        $search = $request->get('search');
+
+        $cities = City::query()
+            ->with(['country:id,name'])
+            ->select('id', 'name', 'country_id')
+            ->orderBy('name')
+            ->when(
+                $search,
+                fn (Builder $query) => $query
+                    ->where('name', 'ilike', "%{$search}%")
+            )
+            ->limit(10)
+            ->get();
+
+        return Response::json($cities->values());
+    }
+
+    /**
+     * @return array<string, Type>
+     */
+    public function schema(JsonSchema $schema): array
+    {
+        return [
+            'search' => $schema->string()->description('Teilstring-Suche im Namen der Stadt.'),
+        ];
+    }
+}