Add project README and user tutorial presentation docs

[EndyKaufman]

Motivation

• Provide an entrypoint for contributors and users by adding a top-level project README.md describing repository layout, quick start and common commands.
• Include a slide-based tutorial to present visible UI flows and onboarding screenshots as docs/user-tutorial-presentation.md.
• Reserve an images folder for tutorial assets by adding docs/images/tutorial/.gitkeep so presentation images can be added later.

Description

• Added README.md with repository structure, requirements, quick start instructions, common commands and links to subproject READMEs.
• Added docs/user-tutorial-presentation.md containing a slide-per-section tutorial that documents visible UI screens, expected images paths, and a pre-export checklist.
• Added docs/images/tutorial/.gitkeep to track the tutorial images directory in the repo.
• All changes are documentation-only and do not modify application code or runtime behavior.

Testing

• No automated tests were run for these documentation-only changes.

---

Codex Task