v0.4.0

Security

• Restrict explicit GPU passthrough to recognized GPU character devices under
  /dev, rejecting arbitrary character and block devices.
• Create independent container GPU device nodes with workload ownership and
  mode 0660, preserving non-root GPU access without changing host ownership
  or permissions. Native setup now fails if device creation or ownership
  assignment is unavailable, or a target inode already exists.

Changed

• Upgrade Rust dependencies, including dirs 7, and refresh all transitive
  dependency versions. Adopt the current Landlock no_new_privs API.
• Refresh Nix inputs and the PostgreSQL benchmark lockfile.

Fixed

• Place native GPU devices at their expected /dev/... paths instead of
  /dev/dev/....
• Isolate image-signing keys in unit and integration tests to prevent parallel
  key-creation races on clean systems.
• Satisfy the current stable Clippy byte-string lint.

Tests

• Add a privileged CI regression test verifying root and non-root access to
  private device nodes while preserving the source inode's metadata.

Full changes: v0.3.9...v0.4.0