Restyles the master UI after the Ledger design: a sidebar with live counts,
a machine filter, a Live box and a light/dark toggle; the overview groups
services per Swarm cluster and machine with icons, search and the
Icon / Icon + text / Text switch; the agents page gets a revoke popover and
an add-agent panel with a connect step. Jobs, Job and Service pages get the
new shell and tokens only.
- fonts and Simple Icons are served by the master (no CDN)
- the overview reads agents too, to show offline banners and cluster managers
- revoking an agent also publishes the agents event
- the SSE keepalive is a named event (ping) the Live box counts
- the master passes its build version to the UI so agents on another
version are marked old
Claude-Session: https://claude.ai/code/session_01GAZsp3P7Qto6JnhipxWUJQ
