GenServer implementation for terminal window management in Raxol.

This server provides a pure functional approach to window management, eliminating Process dictionary usage and implementing proper OTP patterns.

Features

• Window creation, destruction, and lifecycle management
• Hierarchical window relationships (parent/child)
• Window state tracking (active, inactive, minimized, maximized)
• Window properties management (title, size, position)
• Icon management for windows
• Supervised state management with fault tolerance

State Structure

The server maintains state with the following structure:

%{
  windows: %{window_id => Window.t()},
  active_window: window_id | nil,
  window_order: [window_id],  # Z-order for stacking
  window_state: :normal | :minimized | :maximized | :fullscreen,
  window_size: {width, height},
  window_title: String.t(),
  icon_name: String.t(),
  icon_title: String.t(),
  spatial_map: %{},  # For spatial navigation
  navigation_paths: %{},  # Custom navigation paths
  next_window_id: integer()
}