Use this skill whenever the user wants an end-to-end workflow for the HCP Young Adult dataset, including dataset download, organization, and multimodal processing of sMRI, fMRI, and DTI. Triggers include: 'HCP Young Adult', 'HCP1200', 'process HCP data', 'HCP sMRI fMRI DTI', or any request to run the full HCP multimodal pipeline. This is the NeuroClaw modality-orchestration layer: it plans WHAT to do and delegates execution to other skills.