✨ Add restore_point functionality to Meetups

- 💾 Introduced `restore_point` JSON column in `meetups` table for saving and restoring master data.
- 🛠️ Added methods `captureRestorePoint` and `restoreFromRestorePoint` to `Meetup` model for managing restore points.
- 🔒 Implemented authorization for updating meetups via `updateViaPortal` policy to include pivot members.
- 🔗 Created Artisan commands `meetups:snapshot` and `meetups:restore` for managing restore points from CLI.
- 🚦 Added rate limiter to restrict excessive update attempts in Livewire meetup editing.
- ✅ Developed exhaustive feature tests for snapshot and restore actions, portal editing rules, and rate limiting.

app/Policies/MeetupPolicy.php

@@ -29,4 +29,16 @@ class MeetupPolicy
     {
         return $this->owns($user, $meetup);
     }
+
+    /**
+     * Gelockerte Update-Regel ausschließlich für das Portal-Frontend (Livewire):
+     * Neben dem Ersteller darf auch jedes Mitglied der meetup_user-Pivot
+     * („Meine Meetups" im Dashboard) die Stammdaten bearbeiten. REST-API und
+     * MCP nutzen weiterhin die strikte update()-Ability. Übergangslösung, bis
+     * ein echtes Rollen-/Freigabekonzept existiert.
+     */
+    public function updateViaPortal(User $user, Meetup $meetup): bool
+    {
+        return $this->owns($user, $meetup) || $meetup->hasMember($user);
+    }
 }