## Summary
- Add `MemfdFlags` enum to replace raw integer flags for `memfd_create`,
providing semantic clarity for different use cases (`executable`,
`non_executable`, `cross_process`)
- Add support for `MFD_EXEC` and `MFD_NOEXEC_SEAL` flags (Linux 6.3+)
with automatic fallback to older kernel flags when `EINVAL` is returned
- Use memfd + `/proc/self/fd/{fd}` path for loading embedded `.node`
files in standalone builds, avoiding disk writes entirely on Linux
## Test plan
- [ ] Verify standalone builds with embedded `.node` files work on Linux
- [ ] Verify fallback works on older kernels (pre-6.3)
- [ ] Verify subprocess stdio memfd still works correctly
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude <noreply@anthropic.com>
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