v0.12.3

Demo infrastructure

• Reorganize demos/ — self-contained demo directories (ai-alliance/, opik/) with shared resources (shared/)
• Interactive demo controls — step counter [1/19], Esc to skip section, e to edit/re-run command, q to quit
• Quoted command display — query strings show with "quotes" so users see exact syntax
• cleanup.sh — reset demo collections for a fresh run
• || true guards — demo scripts never abort mid-recording

Fixes

• Opened #59 for backup validate failure during demos

Docs

• Exclude demos/ from markdown linting
• Update Opik checklist — VDB/RAG demo and agents demo marked done

Full Changelog: v0.12.2...v0.12.3