get_gotify_extras() previously only ever surfaced the *resolved* click_url,
never the action_code that produced it -- so the frontend had no way to
know which action_code a notification carried, and got nothing at all for
a code that hasn't been configured in NotificationLink yet. Now
action_code rides along under client::notification.action_code whenever
it's set, independent of whether it resolved to a click_url. Verified live
against a running Gotify container, both resolved and unresolved.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
