Extend service API for Events and fix panel layout reverting during edit.

Service rooms support town_hall/webinar types with source lookup, update, and cancel; stage poll no longer overwrites layout while the modal is open.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/Room.php

@@ -76,6 +76,19 @@ class Room extends Model
         return $this->hasMany(SessionFile::class, 'room_id');
     }
 
+    /**
+     * @param  \Illuminate\Database\Eloquent\Builder<self>  $query
+     */
+    public function scopeForSource($query, string $app, string $entityId, ?string $ownerRef = null): void
+    {
+        $query->where('source->app', $app)
+            ->where('source->entity_id', $entityId);
+
+        if ($ownerRef !== null) {
+            $query->where('owner_ref', $ownerRef);
+        }
+    }
+
     public function isWebinar(): bool
     {
         return $this->type === 'webinar';