✨ feat: Add model performance metrics to dashboard

Add a shared `performance-metrics` feature module for perf metric APIs, DTOs, and formatting, then surface global 24h model performance on the dashboard with cards and a top-model table.

Reuse the shared metrics module from pricing model details, remove duplicated perf API/formatting code from pricing, and add localized labels for the new dashboard performance UI.

web/default/src/features/performance-metrics/lib/format.ts

@@ -0,0 +1,16 @@
+export function formatThroughput(tps: number): string {
+  if (tps <= 0) return '—'
+  if (tps >= 1_000) return `${(tps / 1_000).toFixed(1)}K t/s`
+  return `${tps.toFixed(tps < 10 ? 2 : 1)} t/s`
+}
+
+export function formatLatency(ms: number): string {
+  if (!Number.isFinite(ms) || ms <= 0) return '—'
+  if (ms >= 1_000) return `${(ms / 1_000).toFixed(2)}s`
+  return `${Math.round(ms)}ms`
+}
+
+export function formatUptimePct(pct: number): string {
+  if (!Number.isFinite(pct)) return '—'
+  return `${pct.toFixed(2)}%`
+}