[mikecerisano]

./test.sh engine-test could exit with a SwiftPM failure on Xcode 27.1 after running Swift Testing but never loading its arm64 XCTest bundle: the mixed runner chose an arm64e host. Run XCTest and Swift Testing in separate explicit invocations, preserving sequential fixture execution and a failing exit if either half fails.

The real-exFAT handoff fixture now writes immediate hdiutil create/attach/detach start and elapsed-time lines to stderr. This makes a slow disk-image operation visible instead of making the previous XCTest output boundary look like the stalled test. It keeps the existing non-force detach and leaves mounted scratch intact on cleanup failure.

Local validation on Xcode 27.1:

• ./test.sh engine-test: XCTest 129 tests, 17 expected skips, zero failures; Swift Testing 163 reported tests in 33 suites, six skipped test entries, zero failures.
• All eight Issue Hardware test: Crashes upon completion & mid-transfer #10 disposable images attached and detached successfully. The longest detach in this run was 8.6 seconds. An earlier isolated XCTest run took 242 seconds under load, and process inspection showed hdiutil create/detach activity after DestinationTraversalPermissionsTests had already passed.
• bash -n test.sh and git diff --check pass.

This changes test orchestration and fixture diagnostics only. It does not alter production file access, entitlements, transfer safety checks, or release behavior. Hosted CI has separate existing toolchain/compiler failures; no manual CI rerun was requested.