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>

frontend/package-lock.json

@@ -1,13 +1,14 @@
 {
   "name": "stackpilot-frontend",
-  "version": "0.26.0",
+  "version": "0.29.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "stackpilot-frontend",
-      "version": "0.26.0",
+      "version": "0.29.0",
       "dependencies": {
+        "@fontsource-variable/schibsted-grotesk": "^5.2.8",
         "@monaco-editor/react": "^4.6.0",
         "@tanstack/react-query": "^5.62.7",
         "@xterm/addon-fit": "^0.10.0",
@@ -346,6 +347,15 @@
         "node": ">=12"
       }
     },
+    "node_modules/@fontsource-variable/schibsted-grotesk": {
+      "version": "5.2.8",
+      "resolved": "https://registry.npmjs.org/@fontsource-variable/schibsted-grotesk/-/schibsted-grotesk-5.2.8.tgz",
+      "integrity": "sha512-nZAorDrFue4dXZbI613WdvAhu5DPH1UJYNn5fWl7Poa+nl/s9o3VUcQImIiVZpQnYG/jkPVzHsTE7WZbSDvvkw==",
+      "license": "OFL-1.1",
+      "funding": {
+        "url": "https://github.com/sponsors/ayuhito"
+      }
+    },
     "node_modules/@jridgewell/gen-mapping": {
       "version": "0.3.13",
       "resolved": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.13.tgz",