Implementation stopped at the plan's route-generation STOP gate.
Sanitized evidence: the required admin build succeeds, but deleting _dash/sandbox.tsx and regenerating apps/admin/src/routeTree.gen.ts also changes unrelated existing route contracts (/orders/, /products/, and /purchases/ normalize without trailing slashes, and the dashboard root generated full path changes). Those changes are not references made invalid solely by the sandbox deletion, so accepting them would exceed D-01 scope; hand-editing generated output is expressly prohibited.
No external owner or active consumer was found in repository references, public issue/PR search, or file history for the named stale surfaces. No delivery commit or PR was created. Human decision is required on whether to accept the generator-wide route normalization or first land a separate generated-route baseline update.