QA review of 88a4ae9 caught that UpgradeTest.php requires peptide-search-ai.php
(to access the pure helper psa_upgrade_needed) but did not stub add_action or
add_filter. The plugin file calls those at top level (lines 47, 53, 146, 265),
so the test would fatal on load with "Call to undefined function add_action".
Follows the stub pattern used in PostTypeTest.php.
Agent-Session: cowork-qa-p1-fixes-20260414
61cf00c322