AuraScan v0.1.0 developer preview

Initial public developer preview of AuraScan.\n\nHighlights:\n- Conservative Arch/CachyOS package audit flow for pacman hooks and PKGBUILD review.\n- Structured terminal and JSON reporting.\n- Deep static analysis remains explicit and opt-in.\n- Smart update fast path remains gated by context proof, trusted baseline, and trust-boundary diff checks.\n\nThis release is source-only for early review and development.