iOS UI testing toolkit with screenshot validation. Use when:
(1) Setting up UI test infrastructure with Page Object pattern
(2) Creating accessibility identifiers with structured naming
(3) Writing UI tests with step-by-step screenshots
(4) Validating UI via screenshot comparison
(5) Writing snapshot tests with swift-snapshot-testing
(6) Comparing snapshot diffs with snapshotsdiff CLI
(7) Integrating with Allure for test reporting
(8) Organizing shared test identifiers between app and test targets
File types: Swift UI tests, XCUITest, xcresult, Allure reports, snapshot tests