Match the Windows missing volume-serial exception while retaining strict reported-device, inode, ownership, permission, link and snapshot checks. Add loader warning/block and race regression controls with isolated platform metadata injection.
Open with supported no-follow and nonblocking flags before relying on file metadata. Validate descriptor, pathname and rule-directory consistency before and after reading at most64KiB plus one overflow byte. Reject observed replacement, mutation, premature EOF and non-regular files, and close descriptors on every outcome.
Add12 race and I/O regressions. Keep the Hermes uppercase protected-file fixture real on case-sensitive filesystems and verify that the installed guard still permits first-time creation.
Validation: full6688 reported tests across347 files,12 race tests, full80% coverage gates, scoped Hookify coverage, installed Hookify and Hermes workflows, packed artifact lifecycle, lint, signatures and IOC.