Support SQLite dashboard time calculations

app/Livewire/Dashboard/DashboardPage.php

@@ -6,6 +6,7 @@ use App\Models\ActivityLog;
 use App\Models\ServiceRequest;
 use App\Models\Status;
 use App\Models\User;
+use App\Support\DatabaseExpression;
 use Illuminate\Database\Eloquent\Builder;
 use Livewire\Attributes\Layout;
 use Livewire\Component;
@@ -47,7 +48,7 @@ class DashboardPage extends Component
         $this->avgResolutionHours = (float) (ServiceRequest::query()
             ->whereNotNull('completed_at')
             ->whereDate('completed_at', '>=', now()->subDays(30))
-            ->selectRaw('AVG(TIMESTAMPDIFF(HOUR, created_at, completed_at)) as avg_hours')
+            ->selectRaw('AVG('.DatabaseExpression::hoursBetween('created_at', 'completed_at').') as avg_hours')
             ->value('avg_hours') ?? 0);
 
         $this->statusChart = Status::query()