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/main.py

@@ -19,6 +19,7 @@ from routers import (
     auth,
     backups,
     containers,
+    dashboard,
     destinations,
     editor,
     files,
@@ -57,7 +58,7 @@ async def lifespan(app: FastAPI):
     schedule_task.cancel()
 
 
-app = FastAPI(title="StackPilot", version="0.29.0", lifespan=lifespan)
+app = FastAPI(title="StackPilot", version="0.30.0", lifespan=lifespan)
 
 app.add_middleware(
     CORSMiddleware,
@@ -80,6 +81,7 @@ app.include_router(auth.router)
 app.include_router(stacks.router)
 app.include_router(secrets.router)
 app.include_router(containers.router)
+app.include_router(dashboard.router)
 app.include_router(system.router)
 app.include_router(volumes.router)
 app.include_router(editor.router)