fix(dashboard): keep unverified users on enroll page after join

After email login, auto-enroll was redirecting to /lms or the admin
/courses/:id/lessons route. Unverified users cannot use the LMS yet
(VerifyEmailModal on app routes), which felt like a permission error.

Enroll without verification, but stay on the enroll page with a verify
prompt instead of redirecting until email is confirmed. Also fix custom
domain org lookup to use hostname without backend port.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

apps/dashboard/src/lib/utils/translations/de.json

@@ -892,7 +892,9 @@
         "enroll_page": {
           "requires_payment_or_invite": "Sie müssen für diesen Kurs bezahlen oder eingeladen werden, um Zugang zu erhalten.",
           "back_to_course": "Zurück zum Kurs",
-          "join_course": "Nehmen Sie am Kurs teil"
+          "join_course": "Nehmen Sie am Kurs teil",
+          "enrolled_success": "You're enrolled in this course.",
+          "enrolled_verify_email": "You're enrolled! Verify your email to access this course in your learning area."
         },
         "pricing_section": {
           "free": "Kostenlos",