✨ Add leader-based permissions to Meetup event tests and editable scope

- 🔒 Ensure leader users are required for Meetup event tests to simulate accurate permissions.
- ➕ Add `editableBy` scope to `MeetupEvent` model for consistent editable event handling.
- 🛠️ Refactor `mine` API endpoint and MCP tool to leverage `editableBy` scope.
- 🧪 Update tests to verify leader-based accessibility for Meetup events.

app/Models/Meetup.php

@@ -292,7 +292,7 @@ class Meetup extends Model implements HasMedia
      */
     public function scopeLedBy(Builder $query, int $userId): void
     {
-        $query->whereHas('users', fn (Builder $user) => $user->whereKey($userId)->wherePivot('is_leader', true));
+        $query->whereHas('users', fn (Builder $user) => $user->whereKey($userId)->where('meetup_user.is_leader', true));
     }
 
     /**

app/Models/MeetupEvent.php

@@ -6,6 +6,7 @@ use App\Enums\RecurrenceType;
 use App\Enums\RsvpStatus;
 use App\Observers\MeetupEventObserver;
 use Illuminate\Database\Eloquent\Attributes\ObservedBy;
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
@@ -55,6 +56,18 @@ class MeetupEvent extends Model
         });
     }
 
+    /**
+     * Termine, die der Nutzer bearbeiten darf: selbst angelegt ODER Leader des
+     * zugehörigen Meetups (deckungsgleich mit MeetupEventPolicy::update).
+     */
+    public function scopeEditableBy(Builder $query, int $userId): void
+    {
+        $query->where(function (Builder $query) use ($userId) {
+            $query->where('created_by', $userId)
+                ->orWhereHas('meetup', fn (Builder $meetup) => $meetup->ledBy($userId));
+        });
+    }
+
     public function createdBy(): BelongsTo
     {
         return $this->belongsTo(User::class, 'created_by');