include two examples with AIDRIN

[jeanbez]

Adds two end-to-end DSAgt use-cases showing the agent registers the AIDRIN (https://github.com/idtlab/AIDRIN) CLI (develop branch) and drives it as an AI-data-readiness gate, with full dsagt-run provenance:

• AIDRIN Readiness Gate (Cryo-EM): runs AIDRIN's quality/impact metrics before and after cryo-EM particle curation (EMPIAR-10017) to measure the readiness delta; privacy/fairness metrics deliberately excluded as N/A for particle data.
• Full AIDRIN Feature Tour: exercises all 15 metrics (quality, impact, fairness, governance) on the bundled example dataset.

Each walkthrough covers AIDRIN installation, tool registration, metric execution, datacard generation, and pipeline reconstruction. Wired into the docs site (docs/use-cases/, mkdocs.yml nav) and the README use-case table.

[aarontuor]

Approving this since the changes are isolated to new files. I'll merge to main and pull changes into the feat/skills-management branch to walk through examples and test workflow.