Codex re-gate found two issues in the uncapped-read fix: (1) open_anchored_fd
opens blocking O_RDONLY, which HANGS on a workspace FIFO/special file swapped in
at a regular-file path; (2) the non-regular fstat branch returned without
closing the fd (leak). Fix: lstat the symlink-resolved target BEFORE any open to
skip non-regular leaves (no blocking open on a FIFO), and close the fd on the
non-regular fstat branch. Adds a threaded FIFO-no-hang regression test.
Codex regression gate found that routing workspace reads through
read_file_content() introduced a 400KB MAX_FILE_BYTES cap not present on master
(Path.read_text), so a large but legitimate workspace file raised ValueError ->
caught -> None -> the rollback diff falsely reported it as DELETED. Replace with
an uncapped anchored O_NOFOLLOW read (safe_resolve_ws + open_anchored_fd +
S_ISREG fstat check) that keeps the symlink-escape protection but has no size
cap. Adds a >400KB regression test (RED on the capped path, GREEN with the fix).
Co-authored-by: Hinotoi-agent <Hinotoi-agent@users.noreply.github.com>