security: sandbox hardening, scrubber patterns, /api/sandbox/test endpoint, SecurityView update

redesign: professional landing page with Linear/Vercel-inspired design

docs: getting started guide + double-click launcher for non-technical users

fix: auto-detect OS, show correct install command for Windows/Mac/Linux

fix: vercel deployment + all panels working

fix: add vercel.json to serve landing/ correctly

feat: VikingClaw v1.0 — local-first AI agent