Publish one end-to-end ecosystem walkthrough spanning all sibling libraries

[cmccomb]

Why

design-research is intentionally a convenience layer, so its main user-facing value should be composed workflow clarity rather than extra implementation. The current umbrella framing explains the sibling roles well, but the public example stops at top-level discovery and import checks.

If the ecosystem is meant to feel independently useful and superpowered together, the umbrella package should make the combined path obvious.

Proposed work

• Add one canonical walkthrough that starts with a problem, binds an agent, runs a small experiment, and analyzes the resulting artifacts.
• Keep the walkthrough public-API-first and runnable from the umbrella namespace.
• Include one diagram showing the handoff points between problems, agents, experiments, and analysis.
• Link the walkthrough prominently from the README, docs homepage, and examples index.

Acceptance criteria

• There is one public docs page that demonstrates a minimal end-to-end workflow across all four sibling libraries.
• The example produces and then consumes canonical experiment artifacts rather than stopping at imports.
• The page calls out when umbrella imports are sufficient and when direct sibling imports are appropriate.
• The walkthrough is prominently linked from the umbrella README/docs home.