Reports: Align the meetup details export guard with sibling reports

[obenland]

Meetup_Details::export_to_file() combined its nonce and capability checks with &&, so the early-return guard did not require both conditions to hold. Every other report class in the plugin writes this guard so that both a valid run-report nonce and the view_wordcamp_reports capability are required — see class-meetup-events.php, class-meetup-sponsors.php, and class-wordcamp-details.php. This makes Meetup_Details consistent with them.

-		if ( ! wp_verify_nonce( $nonce, 'run-report' ) && current_user_can( CAPABILITY ) ) {
+		if ( ! wp_verify_nonce( $nonce, 'run-report' ) || ! current_user_can( CAPABILITY ) ) {
 			return;
 		}

How to test the changes in this Pull Request:

1. As a user with the view_wordcamp_reports capability, open the Meetup Details report and export the CSV — it downloads as before.
2. Confirm the guard now matches the sibling report classes (both a valid nonce and the capability are required to proceed).

🤖 Generated with Claude Code

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