feat(frontend): expose processing tier pricing

frontend/src/features/usage/components/__tests__/ServiceTierFacts.spec.ts

@@ -0,0 +1,41 @@
+import { afterEach, describe, expect, it } from 'vitest'
+import { createApp, h, type App } from 'vue'
+
+import ServiceTierFacts from '../ServiceTierFacts.vue'
+
+const mountedApps: Array<{ app: App, root: HTMLElement }> = []
+
+afterEach(() => {
+  for (const { app, root } of mountedApps.splice(0)) {
+    app.unmount()
+    root.remove()
+  }
+})
+
+describe('ServiceTierFacts', () => {
+  it('renders all three facts and marks a missing actual tier explicitly', () => {
+    const root = document.createElement('div')
+    document.body.appendChild(root)
+    const app = createApp({
+      render: () => h(ServiceTierFacts, {
+        requested: 'priority',
+        actual: null,
+        billing: 'flex',
+      }),
+    })
+    app.mount(root)
+    mountedApps.push({ app, root })
+
+    expect(root.querySelector('[data-testid="service-tier-facts"]')).not.toBeNull()
+    expect([...root.querySelectorAll('dt')].map(node => node.textContent?.trim())).toEqual([
+      '请求层级',
+      '实际层级',
+      '计费层级',
+    ])
+    expect([...root.querySelectorAll('dd')].map(node => node.textContent?.trim())).toEqual([
+      'priority',
+      '-',
+      'flex',
+    ])
+  })
+})

frontend/src/features/usage/components/__tests__/UsageRecordsTable.spec.ts

@@ -295,6 +295,22 @@ describe('UsageRecordsTable', () => {
     expect(root.textContent).toContain('fast')
   })
 
+  it('uses the actual service tier when the provider changes processing class', () => {
+    const downgraded = mountUsageRecordsTable([buildRecord({
+      service_tier: 'priority',
+      actual_service_tier: 'default',
+    })])
+    expect(downgraded.textContent).not.toContain('fast')
+    expect(downgraded.querySelector('[title*="Requested service tier: priority"]')).not.toBeNull()
+    expect(downgraded.querySelector('[title*="Actual service tier: default"]')).not.toBeNull()
+
+    const upgraded = mountUsageRecordsTable([buildRecord({
+      service_tier: 'flex',
+      actual_service_tier: 'priority',
+    })])
+    expect(upgraded.textContent).toContain('fast')
+  })
+
   it('offers embedding API formats in the usage record filter', () => {
     const root = mountUsageRecordsTable([buildRecord({ api_format: 'openai:chat' })])