sequenceDiagram
    participant Sidebar as ProjectSidebar
    participant ProjectNav as ProjectNavigation
    participant FavoritesNav as useFavoriteNavItems
    participant ProjectsStore as ProjectsStore
    participant Constants as projects.constants
    participant ProjectSettings as ProjectSettings

    Note over Sidebar,ProjectSettings: Render-time fallback for null project icons

    Sidebar->>ProjectNav: render sidebar items
    ProjectNav->>ProjectsStore: getProjectList()
    ProjectsStore-->>ProjectNav: project list (icon may be null)
    
    alt project.icon is null
        ProjectNav->>Constants: import DEFAULT_PROJECT_ICON (icon: 'layers')
        ProjectNav->>ProjectNav: render fallback icon from constant
    else project.icon exists
        ProjectNav->>ProjectNav: render project.icon as-is
    end

    Sidebar->>FavoritesNav: getFavoriteProjectItems()
    FavoritesNav->>ProjectsStore: get project by resourceId
    alt project found AND project.icon is null
        FavoritesNav->>Constants: import DEFAULT_PROJECT_ICON
        FavoritesNav->>FavoritesNav: use fallback icon
    else project found AND project.icon exists
        FavoritesNav->>FavoritesNav: use project.icon
    else project not found (favorited but data not loaded)
        FavoritesNav->>Constants: import DEFAULT_PROJECT_ICON
        FavoritesNav->>FavoritesNav: use fallback icon
    end
    FavoritesNav-->>Sidebar: menu items with resolved icon

    Note over ProjectSettings: Project settings page initializes icon state
    ProjectSettings->>Constants: import DEFAULT_PROJECT_ICON
    ProjectSettings->>ProjectSettings: initialize projectIcon ref from constant copy

    Note over Constants: Shared constant used by all consumers
    Constants->>Constants: defines DEFAULT_PROJECT_ICON = {type:'icon', value:'layers'}