`cy.get` inside `.within(<tree node>)` only searches that node, and the metadata accordion renders in the content area - so `.clr-accordion-header-button` was never found however long it retried. The spec queries the accordion at document level, selects the first metadata type by its class rather than by node index, and clicks the header button directly (Clarity puts `clr-accordion-header-button` on the button itself). The assertions are on the app's own markers: the single open panel (`clr-accordion-panel-open`, `aria-expanded`), the association tree inside the panel, and the attribute grid that `metanav/metadetails` fills. metanav moves from EXCLUDED to SPECS in `.gitea/scripts/cypress-specs.sh`. Closes #395.