Email change fails with generic error

[mattobee]

Description

Clicking "Update email" on the account page shows: "There was a problem updating your email address."

The client-side code calls supabase.auth.updateUser({ email }, { emailRedirectTo }) which returns an error, but the actual Supabase error message is sanitized away. The root cause is unknown.

Investigation leads

1. Redirect URL allow-list — the emailRedirectTo URL (/auth/callback?next=...) may not be added to Supabase Dashboard > Authentication > URL Configuration > Redirect URLs. Deploy preview URLs need to be in the allow-list.
2. "Secure email change" setting — if enabled in Supabase Dashboard > Authentication > Providers > Email, the flow sends confirmation to both old and new email addresses. This may affect the expected behaviour.
3. SMTP rate limits — the built-in Supabase SMTP has strict rate limits which could cause failures.

Steps to reproduce

1. Log in with an email/password account on a deploy preview
2. Go to /account
3. Enter a new email address in the "Change email" field
4. Click "Update email"
5. Error callout appears

Next steps

• Add console.error('[email change]', error.message, error) temporarily to the error handler in src/pages/account.astro (line ~348) to capture the actual Supabase error
• Check Supabase Dashboard > Authentication > URL Configuration for the redirect allow-list
• Check Supabase Dashboard > Authentication > Providers > Email for the "Secure email change" toggle