2ecb18c4a7
One-shot windows-latest E2E: launches real Chrome on a user-data-dir so it holds the cookie DB with a Windows share lock, asserts a RAW copy fails (WinError 32 precondition — else skip, no vacuous green), then asserts _copy_auth_file copies it via SQLite online-backup and the result is a readable Cookies DB with the cookies table. This proves the Windows 'file in use' fix on a real runner — the coverage the Linux lanes cannot provide. PROOF branch evidence only: this workflow + test are reverted before merge and must never land on main.