feat(persons): add confirm dialog to provisional confirm action

Confirming a provisional person was a one-click write — easy to fat-finger
on a touchscreen and irreversible (the person disappears from the review
list, with no obvious undo path). Mirror the destructive-delete pattern
with a non-destructive confirm dialog (destructive: false) so the action
requires a second deliberate click.

New i18n keys (persons_review_confirm_confirm_title/text/button) added
to all three locales (de, en, es).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/lib/person/PersonReviewRow.svelte

@@ -62,7 +62,19 @@ const deleteBtn =
 			>
 				{m.persons_review_action_rename()}
 			</button>
-			<form method="POST" action="?/confirm" use:enhance>
+			<form
+				method="POST"
+				action="?/confirm"
+				use:enhance={async ({ cancel }) => {
+					const ok = await confirm({
+						title: m.persons_review_confirm_confirm_title(),
+						body: m.persons_review_confirm_confirm_text(),
+						confirmLabel: m.persons_review_confirm_confirm_button(),
+						destructive: false
+					});
+					if (!ok) cancel();
+				}}
+			>
 				<input type="hidden" name="id" value={person.id} />
 				<button type="submit" class={actionBtn}>{m.persons_review_action_confirm()}</button>
 			</form>