docs(spec): add SPEC-002 GuruConnect v2 modernization architecture
Ground-up v2 re-architecture decided 2026-05-29 (Mike), grounded in the
2026-05-29 audit + adopted GuruRMM design principles. Greenfield salvaging
proven Rust cores (DXGI/GDI capture, input injection, SAS helper, prost codec,
CI). Native-first full key fidelity (Win+R/Ctrl+Alt+Del) + bidirectional file
transfer (clipboard cut/paste + drag-and-drop) as headline differentiators;
WebRTC fallback only. Hardened single-tenant, tenancy-ready schema. Standalone-
first + /api/integration/v1 RMM contract. Closes all audit CRITICALs by design.
Open decisions resolved: in-place repo reset, H.264 default, WSS-first web
transport, widened support codes, clean v1 cutover (no client migration).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>