feat: add isUserEligible() hook to IPolicyDefinition interface

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/Policy/Contract/IPolicyDefinition.php

@@ -34,4 +34,11 @@ public function defaultSystemValue(): mixed;
 	 * that must never appear in the user preferences screen.
 	 */
 	public function supportsUserPreference(): bool;
+
+	/**
+	 * Checks whether the given user is eligible to use this policy.
+	 * Returns false if the user lacks permissions or required context (e.g., not in any signing group).
+	 * Returns true by default if not overridden by specific policies.
+	 */
+	public function isUserEligible(PolicyContext $context): bool;
 }