✨ 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).

tests/Feature/Mcp/MeetupEventMcpToolTest.php

@@ -0,0 +1,72 @@
+<?php
+
+use App\Mcp\Servers\EinundzwanzigServer;
+use App\Mcp\Tools\MeetupEvent\CreateMeetupEventTool;
+use App\Mcp\Tools\MeetupEvent\ListMyMeetupEventsTool;
+use App\Mcp\Tools\MeetupEvent\ShowMyMeetupEventTool;
+use App\Mcp\Tools\MeetupEvent\UpdateMeetupEventTool;
+use App\Models\Meetup;
+use App\Models\MeetupEvent;
+use App\Models\User;
+
+it('lets an authenticated user create a meetup event and stamps created_by', function () {
+    $user = User::factory()->create();
+    $meetup = Meetup::factory()->create();
+
+    $response = EinundzwanzigServer::actingAs($user)->tool(CreateMeetupEventTool::class, [
+        'meetup_id' => $meetup->id,
+        'start' => '2026-08-01 18:00:00',
+        'location' => 'Marktplatz',
+    ]);
+
+    $response->assertOk()->assertSee('Marktplatz');
+
+    $this->assertDatabaseHas('meetup_events', [
+        'location' => 'Marktplatz',
+        'created_by' => $user->id,
+    ]);
+});
+
+it('fails validation for missing fields', function () {
+    EinundzwanzigServer::actingAs(User::factory()->create())
+        ->tool(CreateMeetupEventTool::class, [])
+        ->assertHasErrors();
+});
+
+it('lets the owner update a meetup event', function () {
+    $user = User::factory()->create();
+    $meetupEvent = MeetupEvent::factory()->create(['created_by' => $user->id]);
+
+    EinundzwanzigServer::actingAs($user)
+        ->tool(UpdateMeetupEventTool::class, ['id' => $meetupEvent->id, 'location' => 'Rathaus'])
+        ->assertOk()
+        ->assertSee('Rathaus');
+});
+
+it('forbids updating someone elses meetup event', function () {
+    $owner = User::factory()->create();
+    $meetupEvent = MeetupEvent::factory()->create(['created_by' => $owner->id]);
+
+    EinundzwanzigServer::actingAs(User::factory()->create())
+        ->tool(UpdateMeetupEventTool::class, ['id' => $meetupEvent->id, 'location' => 'Hijack'])
+        ->assertHasErrors();
+});
+
+it('returns only own meetup events in the mine list', function () {
+    $user = User::factory()->create();
+    MeetupEvent::factory()->count(2)->create(['created_by' => $user->id]);
+    MeetupEvent::factory()->create(['created_by' => User::factory()->create()->id]);
+
+    EinundzwanzigServer::actingAs($user)
+        ->tool(ListMyMeetupEventsTool::class)
+        ->assertOk();
+});
+
+it('forbids viewing someone elses meetup event in mine show', function () {
+    $owner = User::factory()->create();
+    $meetupEvent = MeetupEvent::factory()->create(['created_by' => $owner->id]);
+
+    EinundzwanzigServer::actingAs(User::factory()->create())
+        ->tool(ShowMyMeetupEventTool::class, ['id' => $meetupEvent->id])
+        ->assertHasErrors();
+});