#4174 refactor(apple): support managed XCTest runner launchers

Summary

Support managed XCTest launchers through the existing Apple runner session owner. Local and forwarded runners share command recovery, cancellation, retention, shutdown, and log flushing. Add authenticated HTTP endpoints and explicit listener binding while preserving local Xcode launch mechanics and loopback defaults.

This is the first layer requested in review, across 42 files. The Apple provider hooks and Limrun AX-to-native-runner switch follow in separate branches.

Validation

Tested 053fa0f2ee1c369b7b330d1e4829b7c553e36fe6, based on 7b3f63fea.

• pnpm check: passed, exact-commit receipt. 17,000 tests passed; one skipped.
• iOS and macOS native builds passed with identical Swift sources.
• Local iOS 26.4: open Settings, snapshot, selector press, fill, close/reopen; the runner session ID was reused.
• Isolated mutation checks detect failed termination, premature publication, and premature global shutdown.

Commands, output, device details, regression proof, and receipt. GitHub coverage and native/device lanes remain CI obligations.