Node.js 24 (Krypton) entered Active LTS on 2026-02-09. Update all
Dockerfiles, CI pipelines, and engine constraint from node:20-alpine
to node:24-alpine. Corrected .trivyignore: tar CVEs come from Next.js
16.1.6 bundled tar@7.5.2 (not npm). Orchestrator and API images are
clean; web image needs Next.js upstream fix.
Fixes#367
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>