Visual pass: inspiration-style metric cards on Usage and service detail

- Service detail strip: EnhancedMetricCard with CPU sparkline, memory
  gauge, RX-rate sparkline, instance count — real telemetry or honest
  empty states, seeded series only in demo mode
- Usage: host monitoring becomes CPU sparkline + memory gauge + disk
  segmented-bar trio; build stats upgraded to EnhancedMetricCard with a
  real builds-per-day bar chart
- DonutChart: fix gauge geometry — arc baseline was below the viewBox,
  so only a sliver rendered; also fix SegmentedBar dynamic Tailwind
  class that never compiled
- auth sidecar: trust localhost:5175 origin for the second dev server

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/auth/src/auth.js

@@ -78,8 +78,10 @@ const trustedOrigins = [
   'http://localhost:3001',
   'http://localhost:5173',
   'http://localhost:5174',
+  'http://localhost:5175',
   'http://127.0.0.1:5173',
   'http://127.0.0.1:5174',
+  'http://127.0.0.1:5175',
 ]
   .map((origin) => (origin || '').trim())
   .filter(Boolean);