#3403 Docs: dashboard reference needs the Workers view (/dashboard/workers)

swamp-club#3356 (swamp PR #3078) adds a Workers view to the swamp serve --dashboard SPA at /dashboard/workers, and the manual doesn't cover it yet.

Pages to update

• content/manual/reference/swamp-serve/dashboard.md
  • The URL patterns table needs a /dashboard/workers → Workers row.
  • A short Workers section next to Schedules and Approvals:
    • Grouping: remote-execution workers are grouped by the fleet label (the enrollment token), any other label key, or platform/arch, in a treemap weighted by slot capacity.
    • Workers: each worker is a square sized by capacity, with one cell per dispatch slot showing that slot's step lease. A slot is green while its lease is active, then shows completed, failed or expired before it frees.
    • Status outlines: busy workers are outlined green, draining orange and disconnected red.
    • Visibility TTL: disconnected workers stay visible for a TTL the viewer can adjust (default 2h, at most 24h, the worker GC default).
    • Placement selector: you type labels, platform or target the way a step's placement block does. Workers the step wouldn't reach are dimmed, and the view shows how many workers match and how many free slots they have.
    • Slot links: each slot row links to the workflow run it is serving.
    • Access: the view needs an admin grant on access, the same as swamp worker list.
  • The Overview description should mention the header's Workers │ busy · idle · unavailable summary, which links to the Workers view.
• content/manual/how-to/worker-fleets.md and reference/remote-execution.md: one line pointing to the Workers view as the visual way to inspect the pool alongside swamp worker list.

Reference behaviour for writers

• design/primitives/serve.md, the Workers view bullet.
• design/enablers/remote-execution.md, Worker state is swamp data.
• The JSON output of swamp worker list now also includes tokenName and disconnectedAt. Both fields are additive.