✨ 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/api.ts

@@ -0,0 +1,24 @@
+import { api } from '@/lib/api'
+import type { PerformanceMetricsData, PerfSummaryAllData } from './types'
+
+export async function getPerfMetricsSummary(
+  hours = 24
+): Promise<PerfSummaryAllData> {
+  const res = await api.get<PerfSummaryAllData>('/api/perf-metrics/summary', {
+    params: { hours },
+  })
+  return res.data
+}
+
+export async function getPerfMetrics(
+  modelName: string,
+  hours = 24
+): Promise<PerformanceMetricsData> {
+  const res = await api.get<PerformanceMetricsData>('/api/perf-metrics', {
+    params: {
+      model: modelName,
+      hours,
+    },
+  })
+  return res.data
+}