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/ci-runners.md

@@ -50,7 +50,9 @@ native bootstrap and checkout were verified in Mac job 1062 (run 661/#6).
 That job subsequently stalled in Apple-tool preflight after printing Xcode 27.1.
 The preflight now prints each tool probe and bounds it to 60 seconds using Python
 (`scripts/check-apple-tools.py`), so the next run identifies the unresponsive
-command rather than hanging silently. This does not validate the iOS app.
+command rather than hanging silently. Follow-up job 1066 (run 663/#8) verified the
+diagnostic: Xcode and Swift lookup pass, but `xcrun simctl list devices available`
+times out. This is a runner prerequisite failure, not an iOS application test.
 
 If an Apple probe stalls, run the named command in the runner user's interactive
 login session, check the selected full Xcode, finish its first-launch components