fix: allow admin role to access triage and investigation pages

Role guard was hse-only — admin was redirected to inbox on click.
Both triage and investigation now accept hse or admin.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CPf5Rc8QPx6V8KLEEgfKEQ

app/(protected)/hse/incidents/[id]/investigation/page.tsx

@@ -18,7 +18,7 @@ export default async function InvestigationPage({ params }: Props) {
 
   const { data: profile } = await supabase
     .from('users').select('role').eq('id', data.user.id).single()
-  if (!profile || profile.role !== 'hse') redirect('/hse/incidents')
+  if (!profile || !['hse', 'admin'].includes(profile.role)) redirect('/hse/incidents')
 
   const { data: incident } = await supabase
     .from('incidents')