fix: 修正用量失败状态判断与 Codex 会话头

frontend/src/features/usage/utils/__tests__/status.spec.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it } from 'vitest'
+
+import { isUsageRecordFailed, isUsageRecordSuccessful } from '../status'
+import type { UsageRecord } from '../../types'
+
+function buildUsageRecord(overrides: Partial<UsageRecord> = {}): UsageRecord {
+  return {
+    id: 'usage-1',
+    model: 'gpt-5',
+    input_tokens: 10,
+    output_tokens: 20,
+    total_tokens: 30,
+    cost: 0,
+    is_stream: false,
+    created_at: '2026-04-10T00:00:00Z',
+    status: 'completed',
+    ...overrides
+  }
+}
+
+describe('usage status helpers', () => {
+  it('treats explicit completed status as authoritative over stale legacy failure fields', () => {
+    const record = buildUsageRecord({
+      status: 'completed',
+      status_code: 429,
+      error_message: 'rate limited on first attempt'
+    })
+
+    expect(isUsageRecordFailed(record)).toBe(false)
+    expect(isUsageRecordSuccessful(record)).toBe(true)
+  })
+
+  it('falls back to legacy failure signals when status is missing', () => {
+    const record = buildUsageRecord({
+      status: undefined,
+      status_code: 429,
+      error_message: 'rate limited'
+    })
+
+    expect(isUsageRecordFailed(record)).toBe(true)
+    expect(isUsageRecordSuccessful(record)).toBe(false)
+  })
+})

frontend/src/features/usage/utils/status.ts

@@ -0,0 +1,28 @@
+import type { UsageRecord } from '../types'
+
+function hasLegacyFailureSignal(
+  record: Pick<UsageRecord, 'status_code' | 'error_message'>
+): boolean {
+  return (typeof record.status_code === 'number' && record.status_code >= 400) ||
+    (typeof record.error_message === 'string' && record.error_message.trim().length > 0)
+}
+
+export function isUsageRecordFailed(
+  record: Pick<UsageRecord, 'status' | 'status_code' | 'error_message'>
+): boolean {
+  const status = typeof record.status === 'string' ? record.status.trim().toLowerCase() : ''
+  if (status) {
+    return status === 'failed'
+  }
+  return hasLegacyFailureSignal(record)
+}
+
+export function isUsageRecordSuccessful(
+  record: Pick<UsageRecord, 'status' | 'status_code' | 'error_message'>
+): boolean {
+  const status = typeof record.status === 'string' ? record.status.trim().toLowerCase() : ''
+  if (status) {
+    return status === 'completed'
+  }
+  return !hasLegacyFailureSignal(record)
+}