Capture exact filesystem identity and nanosecond timestamps, validate descriptor/path state before and after streaming, and enforce the captured byte count. Bound growing files to their captured size plus one byte using precise positional reads; keep unrepresentable display sizes explicitly unknown.
Reuse the captured-state comparison around Apple assetutil and retain existing reader cleanup ownership. Validation: focused reader and affected consumer suites, full static/architecture checks, and a compiled directory-read probe on Bun 1.3.14 passed. Includes same-size mutation, growth, truncation, cancellation, FIFO replacement, cleanup retry, ZIP identity forgery, ASAR and Mach-O coverage.
Windows has no POSIX execute bit; Node reports file modes from the
read-only attribute alone, so every host file, including PE images,
reported `executable: false` while the same occurrence reported
`artifact_kind: executable`. Derive the host executable marking once:
POSIX permission bits stay authoritative, and Windows marks regular
files with the CreateProcess/cmd launchable extensions.
Fixes#1819
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
morluto