docs: record confirmed CoreSimulator runner blocker

Follow-up Mac job 1066 passed Node/checkout/Xcode/Swift lookup, then correctly failed the bounded simctl device-list probe after sixty seconds. Record the exact administrator-owned blocker without claiming Apple app validation.

docs/validation.md

@@ -71,7 +71,13 @@ Evidence paths in the local external build directory:
   preflight did not return during a 20-minute observation. No SwiftUI compile or
   simulator/XCTest/Keychain/device success is claimed. Bounded, named tool probes
   now fail with actionable diagnostics instead of silently hanging for the job's
-  full hour; their actual next Mac result still needs inspection.
+  full hour.
+- Follow-up iOS run #8 (global 663), job 1066 at `92dbd0e`: Node, checkout,
+  `xcodebuild -version` and `xcrun --find swift` passed. The exact blocker is
+  **`xcrun simctl list devices available`**, which exceeded its 60-second deadline.
+  Preflight correctly failed; application builds/tests/archive were skipped, not
+  passed. The runner administrator must repair CoreSimulator availability for the
+  runner user before Apple application validation can proceed.
 
 No Apple SDK application build, simulator UI test or physical-device result is
 claimed from the Linux runs or the stalled Mac job. Runner prerequisites were