feat: add onboarding checklist widget to dashboard

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/onboarding.ts

@@ -0,0 +1,21 @@
+import { apiClient } from './client'
+
+export interface OnboardingStatus {
+  created_flow: boolean
+  ran_session: boolean
+  exported_session: boolean
+  tried_ai_assistant: boolean
+  invited_teammate: boolean
+  connected_psa: boolean
+  is_team_user: boolean
+  dismissed: boolean
+}
+
+export async function getOnboardingStatus(): Promise<OnboardingStatus> {
+  const response = await apiClient.get('/users/onboarding-status')
+  return response.data
+}
+
+export async function dismissOnboarding(): Promise<void> {
+  await apiClient.post('/users/onboarding-status/dismiss')
+}