Read the workspace-wide Simulations Lab index

One tenant-bound, pure-read DTO for the workspace Simulations Lab page: every suite in the selected project across that project's AI agents, with its latest-run health, plus a bounded agent filter. Omitting project_id selects the workspace's first project rather than merging every project. Latest health is one batch join, never a lookup per suite, so the query count is fixed by the page rather than by how many suites the workspace owns. A suite that has never run reports never_run rather than an invented 0%. The page is bounded with an opaque cursor and an explicit has_more. Returns 404 while Simulations Lab is not enabled.