[Improved, Fixed] Hotfix: candidate search and billing portal errors resolved

Improvements

• Billing page now automatically redirects to the standard Stripe portal if the plan-change flow is unavailable, so users can still manage their subscription without interruption.

Fixes

• Global candidate search is working again; searches for names or emails no longer return a server error.
• Attempting to change a subscription plan in Settings → Billing no longer triggers a 500 error; the correct Stripe page opens as expected.