fix(aci): Restore project-not-found guard in edit.tsx

The !project guard was removed from edit.tsx causing useDetectorFormProject()
to throw when a detector's project is missing or inaccessible. This error
propagates uncaught since the ErrorBoundary in FormSection is too low in
the component tree to catch errors from parent components like AutomateSection
and *IssuePreview components that call useDetectorFormProject() in their body.

Re-adding the guard ensures a friendly 'Project not found' error is shown
instead of crashing the entire page.

Co-authored-by: Armen Zambrano G. <armenzg@users.noreply.github.com>

Author: cursoragent

static/app/views/detectors/edit.tsx

@@ -10,7 +10,7 @@ import {useDetectorQuery} from 'sentry/views/detectors/hooks';
 
 export default function DetectorEdit() {
   const params = useParams<{detectorId: string}>();
-  const {fetching: isFetchingProjects} = useProjects();
+  const {projects, fetching: isFetchingProjects} = useProjects();
   useWorkflowEngineFeatureGate({redirect: true});
 
   const {
@@ -34,6 +34,11 @@ export default function DetectorEdit() {
     );
   }
 
+  const project = projects.find(p => p.id === detector.projectId);
+  if (!project) {
+    return <LoadingError message={t('Project not found')} />;
+  }
+
   return (
     <DetectorFormProvider detectorType={detector.type} detector={detector}>
       <EditExistingDetectorForm detector={detector} />