fix: add cookieless_mode option to PostHog initialization

Author: riderx

src/components/posthog.astro

@@ -49,5 +49,6 @@
     api_host: 'https://psthg.digitalshift-ee.workers.dev/',
     defaults: '2025-05-24',
     person_profiles: 'always',
+    cookieless_mode: 'always',
   })
 </script>