feature: "add header and navigation link to each pages"
mode: full_auto
finalized_at: "2025-12-18T17:07:00"

analysis:
  problem_statement: "The application lacks a consistent navigation header, making it difficult for users to navigate between pages."
  target_users: "All SonicCloud platform users"
  core_value: "Unified navigation and brand identity"

scope:
  mvp_features:
    - Global header component with logo and navigation
    - Navigation links to Home, Search, Playlists, Upload, Profile
    - Responsive design for mobile/desktop
    - User auth state display
    - Root layout integration

components_to_create:
  - id: component_header
    name: Header
    file_path: components/Header.tsx
    purpose: Global navigation header

  - id: component_nav_link
    name: NavLink
    file_path: components/NavLink.tsx
    purpose: Navigation link with active state

  - id: component_user_menu
    name: UserMenu
    file_path: components/UserMenu.tsx
    purpose: User authentication status display

layout_changes:
  - file: app/layout.tsx
    change: Import and render Header component

acceptance_criteria:
  - criterion: "Header appears on all pages"
    verification: "Navigate to each page and verify header presence"
  - criterion: "Navigation links work correctly"
    verification: "Click each link and verify navigation"
  - criterion: "Active state shows current page"
    verification: "Current page is highlighted in navigation"
  - criterion: "Responsive on mobile"
    verification: "Test at mobile viewport width"
  - criterion: "Auth state reflected correctly"
    verification: "Header shows login/register or profile based on auth"