Windows: setup refresh fails (helper_unknown_error) because node_repl.exe in cua_node runtime is locked by Codex's own process (os error 32) #51862

App: ChatGPT/Codex Desktop for Windows, displayed version 26.1002.51308 (package OpenAI.Codex_26.1002.6548.0_x64)
OS: Windows (mini PC). macOS works fine.
Diagnostic session ID: 01a11859-5688-77c6-8874-d7aee74130ab

Symptom:
Every command (even read-only Get-Location) fails before execution:
"exec_command failed: CreateProcess ... helper_unknown_error: setup refresh had errors"

Findings from %USERPROFILE%.codex.sandbox\sandbox.2026-10-07.log:

• The only entry in refresh errors is:
  runtime read/execute validation failed: validate runtime read/execute access on
  C:\Users<user>\AppData\Local\OpenAI\Codex\runtimes\cua_node\2c9e75c4e9c71beb\bin\node_repl.exe:
  open ACL target for root-only update: (os error 32 - sharing violation)
• Write roots are granted successfully; the user-profile ACE also fails with os error 32 but setup continues.
• The cua_node runtime folder was created 2026-10-07 14:29:47 JST; refresh failures start 14:30:55 JST and repeat on every command since. node_repl.exe never appears in earlier logs (up to 2026-10-05), when Windows sessions worked.
• node_repl.exe is running with process chain: codex.exe (Codex\bin\979a96ce184041d1) -> node.exe (cua_node) -> node_repl.exe.
  So the file appears to be locked by Codex's own runtime while the sandbox setup tries to open it for an ACL update.

Expected: setup refresh should not fail on a runtime file held open by Codex itself (or should open it with a compatible share mode).
No local settings, ACLs, or files were modified.