Add zerombr and clearpart commands to ensure clean disk state before installation.
This prevents issues when reinstalling on previously partitioned disks by:
- Reinitializing invalid partition tables (zerombr)
- Removing all partitions from all disks (clearpart --all)
- Writing a fresh disk label (--initlabel)
This makes reinstallation reliable even on disks with previous installations,
while allowing users to override defaults via the GUI if needed.
Add comprehensive FOSS compliance documentation including:
- COPYRIGHT.md: copyright holders and code ownership
- LICENSING.md: GPL-3.0-or-later policy and source offer
- NOTICE: attribution requirements for permissive licenses
- THIRD-PARTY-LICENSES.md: third-party software inventory
- TRADEMARKS.md: trademark notices and non-affiliation
- os-release hook and files: identify FWS as separate from Arch Linux
These documents establish legal compliance baseline for GPL/AGPL/Apache/MIT/BSD obligations before public distribution.