Addresses "chart/gauges don't update" and "design": the visible live layer no
longer depends on the Reverb WS path (which was unreliable through the dev NAT).
- Poller is now the single SSH metrics source: FleetService::applyMetrics writes
the latest reading + a rolling cpu/mem history into the cache (and the DB).
- Dashboard reads latest + history from cache (no SSH on web render); the big
chart and KPI sparklines render real history; wire:poll.10s refreshes them.
- Server-Details gauges read the poller-updated row via wire:poll.10s; the donut
rings get a size="lg" variant (h-24) so they read clearly + animate.
- FleetSeeder no longer seeds a fake fleet (those servers had no credentials and
showed no data). It seeds one real server from CLUSEV_DEMO_SSH_* env vars, or
an empty fleet otherwise. Existing fake servers removed from the demo DB.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>