mac2jb v0.2.1

mac2jb v0.2.1 — maintenance and source packaging update

This release carries the v0.2.0 USB HID sender and ns2jb integration
with targeted maintenance and distribution hardening:

• Included Apple Public Source License 2.0 texts and dated downstream libusbd
  modification notices (already in the repository before these changes).
• Hardened local session directory, pairing file, and GUI host-log permissions.
• Removed bundled precompiled kernel extension and unused upstream USB-device
  proof-of-concept files. Build the kext from the bundled Xcode source project.
• Updated the offline setup and bootstrap-verification helper scripts.
• Added source ZIP checks that reject session captures, machine-local files,
  compiled kernel components, and missing license texts.
• Clarified third-party licensing and provenance of intentionally trimmed
  vendored sources.

Important: This project is experimental and hardware-specific. A successful
USB transfer is not evidence that the console has successfully completed the
ns2jb exploit. Installing a custom kernel extension carries real Mac security
and stability risks. Consult the README before proceeding.