Phase 24: Design System v2 — analytics-style UI (0.30.0)

- New /api/dashboard/funnel (5-stage stack health, 30s TTL cache) and
  /api/dashboard/summary (containers, daily uptime jsonl, ops activity)
- Token system (tokens.css + Tailwind sp-* aliases); legacy bg/card/accent
  remapped onto the tokens; Schibsted Grotesk bundled via fontsource
- TopNav pill navigation + AppShell replace the sidebar layout (off-canvas
  drawer below 1024px); central display-weight page titles
- Dashboard redesign: FunnelChart (gradient/hatch SVG waterfall), container
  count card with per-host bars + Insights chip, UptimeChart, OpsGrid,
  AiPromptBar; 30/7-day range selector; host sections retained below
- Stacks page honours ?q= / ?filter= deep links + new status-filter select

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/agent_app.py

@@ -66,7 +66,7 @@ def _map_docker(exc: DockerError):
         raise HTTPException(status_code=code, detail=exc.detail or exc.error)
     raise exc  # falls through to the global 502 DockerError handler
 
-AGENT_VERSION = "0.29.0"
+AGENT_VERSION = "0.30.0"
 
 
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