The requirements page drew project-request-select, project-north-star
and project-prd with fixed ids, so the same project in both panes put
each id in the document twice. mountContent takes the pane's idPrefix
(pane-a-, pane-b-) and every id and id lookup on the page follows it;
the full view passes none and keeps its ids.
The dashboard was already prefixed and the Agents page draws no ids.
A new browser test opens the same dashboard, Agents page and project
pages in both panes and checks for duplicate ids and for labels, ARIA
references and in-page links that leave their pane.
jason.woltje
fa9bedb09a