PR: https://git.cafe/pingdotgg/t3code/pulls/25167
Head: d82c8d7f90553f476040cf53014e45724a9a3db4
Baseline: github/main 8970a32104e0d37123f33fd122e96826e68b3b4a

Runtime path: Chrome / Playwright -> dev web UI -> real Codex gpt-6.1-sol -> T3 MCP device_close.
Project /home/user/t3code added via the web UI; device hub and agent access enabled in Settings > Devices.

MAIN (web 8693 / server 16733, isolated /home/user/main/.t3):
device_close({"shutdown":true}) without deviceId -> structuredContent {}, isError false.
device_close({"shutdown":false}) without deviceId -> structuredContent {}, isError false.

PR (web 5733 / server 13773, isolated /home/user/t3code/.t3):
device_close({"shutdown":true}) without deviceId -> isError true:
"No device is open in this thread, so nothing was turned off. Pass deviceId to turn a device off."
device_close({"shutdown":false}) without deviceId -> structuredContent {}, isError false.
Confirmed in expanded actual tool details in the web client, not only the model's final text.
Provider recovered after 5 retries; both calls finished within 2 minutes.

BLOCKER:
Installed Java 17, Android SDK command-line tools, emulator, and Android 30 default x86_64 image.
Created AVD pr25167. Started real emulator with:
emulator -avd pr25167 -no-window -no-audio -no-boot-anim -no-snapshot -gpu swiftshader_indirect -memory 1536 -cores 2
adb devices eventually listed emulator-5554 as device, but boot-completion query hung.
Emulator logged:
ERROR | detected a hanging thread 'QEMU2 main loop'. No response for 16404 ms
ERROR | detected a hanging thread 'QEMU2 CPU0 thread'. No response for 16139 ms
ERROR | detected a hanging thread 'QEMU2 main loop'. No response for 18212 ms
Chrome/CDP also timed out while the emulator ran. Stopped captured emulator PID 43078 after stall; browser recovered.
No real device_open / server restart / explicit-device shutdown success is claimed.
No ownership or concurrent-open integration success is claimed. iOS Simulator requires macOS/Xcode.

Startup correction: the first PR dev invocation selected ~/.t3; stopped immediately before any verification call and restarted with explicit --home-dir /home/user/t3code/.t3.
No source changes, commits, or pushes. Existing CI snapshot reports 25 successful checks, zero pending/failing.