feat(timetable): activity log integration per RFC §8

LogOptions on Artist, ArtistEngagement, Stage, Performance, Genre now
list the specific attributes the audit log captures (per §8 last
paragraph) instead of logFillable. Each model gets a distinct
log_name (artist / artist_engagement / stage / performance / genre)
so the activity-log filter can scope queries by domain.

tapActivity() on every model adds organisation_id (and event_id where
relevant) to the activity entry's properties. The audit-log filter in
the SPA can then query
`->where('properties->event_id', $event->id)` without joining through
multiple subject types.

Performance gets dontLogIfAttributesChangedOnly(['updated_at',
'version']) so the bookkeeping touch from PerformanceObserver doesn't
generate noise when nothing user-meaningful changed.

Custom activity events emitted by services for the cases where the
auto-log can't infer intent:

  performance.moved      — LaneCascadeService::move writes a single
                           parent entry with cascade_count and
                           cascaded_ids[] after the cascade-bump
                           commits. Per-row updates still flow
                           through the model trait so the audit log
                           shows both the summary and the diffs.
  stage.day_added /
  stage.day_removed     — StageDayService::replaceDays writes one
                           entry per added/removed event_id, performed
                           on the parent Stage so the log groups by
                           stage rather than by pivot row.
  stage.reordered       — StageService::reorder writes one entry on
                           the parent Event with the full new
                           stage_ids[] order.
  artist_engagement.
    status_changed /
    cancelled            — ArtistEngagementService::transitionStatus
                           emits one of these depending on the target
                           status; pairs with the auto-logged `updated`
                           row.

The remaining artist_engagement.option_expired event lands in Step 10
when the DemoteExpiredOptions command writes a system-causer entry.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/app/Models/Genre.php

@@ -43,8 +43,17 @@ final class Genre extends Model
     public function getActivitylogOptions(): LogOptions
     {
         return LogOptions::defaults()
-            ->logFillable()
-            ->dontLogEmptyChanges();
+            ->logOnly(['name', 'color', 'is_active', 'sort_order'])
+            ->logOnlyDirty()
+            ->dontLogIfAttributesChangedOnly(['updated_at'])
+            ->useLogName('genre');
+    }
+
+    public function tapActivity(Activity $activity, string $eventName): void
+    {
+        $properties = $activity->properties?->toArray() ?? [];
+        $properties['organisation_id'] = $this->organisation_id;
+        $activity->properties = collect($properties);
     }
 
     public function organisation(): BelongsTo