Summary

Implements demo project workflow improvements including:

• Add open demo project option in onboarding screen

  • Adds "Return to your workspace" banner with improved UI and fixed positioning
  • Implements demo project state management (tracking last non-demo project, return hints)
  • Adds modal prompt when returning from demo to real workspace

  Changes

  State Management

  • Added lastNonDemoProjectAtom - tracks the user's last non-demo project
  • Added demoReturnHintPendingAtom & demoReturnHintDismissedAtom - manages demo return flow
  • Added helper functions cacheLastUsedProjectId for persisting project state

  UI Improvements

  • Layout banner: Fixed positioning banner that stays at top while scrolling
  • Replaced text-based banner with actionable "Return to your workspace" button
  • Added modal showing instructions when returning from demo

  OnboardingScreen

  • Updated to use project.is_demo field from API response

  Test Plan

  • Sign up with email/password → verify routed to /post-signup onboarding
  • Complete onboarding → verify placed in demo project
  • Scroll page → verify demo banner stays fixed at top
  • Click "Return to your workspace" button
  • Verify modal appears with instructions (first time)
  • Dismiss modal → verify navigates to last used real workspace
  • Re-enter demo → verify "Do not show again" dismissal is respected